Calculus Examples

$f (x) = 4 x^{2} e^{x} + 10 x e^{x} - 24 e^{x}$

Step 1

Find the first derivative of the function.

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Step 1.1

By the Sum Rule, the derivative of $4 x^{2} e^{x} + 10 x e^{x} - 24 e^{x}$ with respect to $x$ is $\frac{d}{d x} [4 x^{2} e^{x}] + \frac{d}{d x} [10 x e^{x}] + \frac{d}{d x} [- 24 e^{x}]$ .

$\frac{d}{d x} [4 x^{2} e^{x}] + \frac{d}{d x} [10 x e^{x}] + \frac{d}{d x} [- 24 e^{x}]$

Step 1.2

Evaluate $\frac{d}{d x} [4 x^{2} e^{x}]$ .

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Step 1.2.1

Since $4$ is constant with respect to $x$ , the derivative of $4 x^{2} e^{x}$ with respect to $x$ is $4 \frac{d}{d x} [x^{2} e^{x}]$ .

$4 \frac{d}{d x} [x^{2} e^{x}] + \frac{d}{d x} [10 x e^{x}] + \frac{d}{d x} [- 24 e^{x}]$

Step 1.2.2

Differentiate using the Product Rule which states that $\frac{d}{d x} [f (x) g (x)]$ is $f (x) \frac{d}{d x} [g (x)] + g (x) \frac{d}{d x} [f (x)]$ where $f (x) = x^{2}$ and $g (x) = e^{x}$ .

$4 (x^{2} \frac{d}{d x} [e^{x}] + e^{x} \frac{d}{d x} [x^{2}]) + \frac{d}{d x} [10 x e^{x}] + \frac{d}{d x} [- 24 e^{x}]$

Step 1.2.3

Differentiate using the Exponential Rule which states that $\frac{d}{d x} [a^{x}]$ is $a^{x} \ln (a)$ where $a$ = $e$ .

$4 (x^{2} e^{x} + e^{x} \frac{d}{d x} [x^{2}]) + \frac{d}{d x} [10 x e^{x}] + \frac{d}{d x} [- 24 e^{x}]$

Step 1.2.4

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 2$ .

$4 (x^{2} e^{x} + e^{x} (2 x)) + \frac{d}{d x} [10 x e^{x}] + \frac{d}{d x} [- 24 e^{x}]$

Step 1.3

Evaluate $\frac{d}{d x} [10 x e^{x}]$ .

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Step 1.3.1

Since $10$ is constant with respect to $x$ , the derivative of $10 x e^{x}$ with respect to $x$ is $10 \frac{d}{d x} [x e^{x}]$ .

$4 (x^{2} e^{x} + e^{x} (2 x)) + 10 \frac{d}{d x} [x e^{x}] + \frac{d}{d x} [- 24 e^{x}]$

Step 1.3.2

Differentiate using the Product Rule which states that $\frac{d}{d x} [f (x) g (x)]$ is $f (x) \frac{d}{d x} [g (x)] + g (x) \frac{d}{d x} [f (x)]$ where $f (x) = x$ and $g (x) = e^{x}$ .

$4 (x^{2} e^{x} + e^{x} (2 x)) + 10 (x \frac{d}{d x} [e^{x}] + e^{x} \frac{d}{d x} [x]) + \frac{d}{d x} [- 24 e^{x}]$

Step 1.3.3

Differentiate using the Exponential Rule which states that $\frac{d}{d x} [a^{x}]$ is $a^{x} \ln (a)$ where $a$ = $e$ .

$4 (x^{2} e^{x} + e^{x} (2 x)) + 10 (x e^{x} + e^{x} \frac{d}{d x} [x]) + \frac{d}{d x} [- 24 e^{x}]$

Step 1.3.4

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 1$ .

$4 (x^{2} e^{x} + e^{x} (2 x)) + 10 (x e^{x} + e^{x} \cdot 1) + \frac{d}{d x} [- 24 e^{x}]$

Step 1.3.5

Multiply $e^{x}$ by $1$ .

$4 (x^{2} e^{x} + e^{x} (2 x)) + 10 (x e^{x} + e^{x}) + \frac{d}{d x} [- 24 e^{x}]$

Step 1.4

Evaluate $\frac{d}{d x} [- 24 e^{x}]$ .

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Step 1.4.1

Since $- 24$ is constant with respect to $x$ , the derivative of $- 24 e^{x}$ with respect to $x$ is $- 24 \frac{d}{d x} [e^{x}]$ .

$4 (x^{2} e^{x} + e^{x} (2 x)) + 10 (x e^{x} + e^{x}) - 24 \frac{d}{d x} [e^{x}]$

Step 1.4.2

Differentiate using the Exponential Rule which states that $\frac{d}{d x} [a^{x}]$ is $a^{x} \ln (a)$ where $a$ = $e$ .

$4 (x^{2} e^{x} + e^{x} (2 x)) + 10 (x e^{x} + e^{x}) - 24 e^{x}$

Step 1.5

Simplify.

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Step 1.5.1

Apply the distributive property.

$4 (x^{2} e^{x}) + 4 (e^{x} (2 x)) + 10 (x e^{x} + e^{x}) - 24 e^{x}$

Step 1.5.2

Apply the distributive property.

$4 (x^{2} e^{x}) + 4 (e^{x} (2 x)) + 10 (x e^{x}) + 10 e^{x} - 24 e^{x}$

Step 1.5.3

Combine terms.

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Step 1.5.3.1

Multiply $2$ by $4$ .

$4 x^{2} e^{x} + 8 (e^{x} (x)) + 10 (x e^{x}) + 10 e^{x} - 24 e^{x}$

Step 1.5.3.2

Add $8 e^{x} x$ and $10 x e^{x}$ .

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Step 1.5.3.2.1

Move $e^{x}$ .

$4 x^{2} e^{x} + 8 x e^{x} + 10 x e^{x} + 10 e^{x} - 24 e^{x}$

Step 1.5.3.2.2

Add $8 x e^{x}$ and $10 x e^{x}$ .

$4 x^{2} e^{x} + 18 x e^{x} + 10 e^{x} - 24 e^{x}$

Step 1.5.3.3

Subtract $24 e^{x}$ from $10 e^{x}$ .

$4 x^{2} e^{x} + 18 x e^{x} - 14 e^{x}$

Step 1.5.4

Reorder terms.

$4 e^{x} x^{2} + 18 e^{x} x - 14 e^{x}$

Step 1.5.5

Reorder factors in $4 e^{x} x^{2} + 18 e^{x} x - 14 e^{x}$ .

$4 x^{2} e^{x} + 18 x e^{x} - 14 e^{x}$

Step 2

Find the second derivative of the function.

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Step 2.1

By the Sum Rule, the derivative of $4 x^{2} e^{x} + 18 x e^{x} - 14 e^{x}$ with respect to $x$ is $\frac{d}{d x} [4 x^{2} e^{x}] + \frac{d}{d x} [18 x e^{x}] + \frac{d}{d x} [- 14 e^{x}]$ .

$f'' (x) = \frac{d}{d x} (4 x^{2} e^{x}) + \frac{d}{d x} (18 x e^{x}) + \frac{d}{d x} (- 14 e^{x})$

Step 2.2

Evaluate $\frac{d}{d x} [4 x^{2} e^{x}]$ .

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Step 2.2.1

Since $4$ is constant with respect to $x$ , the derivative of $4 x^{2} e^{x}$ with respect to $x$ is $4 \frac{d}{d x} [x^{2} e^{x}]$ .

$f'' (x) = 4 \frac{d}{d x} (x^{2} e^{x}) + \frac{d}{d x} (18 x e^{x}) + \frac{d}{d x} (- 14 e^{x})$

Step 2.2.2

Differentiate using the Product Rule which states that $\frac{d}{d x} [f (x) g (x)]$ is $f (x) \frac{d}{d x} [g (x)] + g (x) \frac{d}{d x} [f (x)]$ where $f (x) = x^{2}$ and $g (x) = e^{x}$ .

$f'' (x) = 4 (x^{2} \frac{d}{d x} (e^{x}) + e^{x} \frac{d}{d x} (x^{2})) + \frac{d}{d x} (18 x e^{x}) + \frac{d}{d x} (- 14 e^{x})$

Step 2.2.3

Differentiate using the Exponential Rule which states that $\frac{d}{d x} [a^{x}]$ is $a^{x} \ln (a)$ where $a$ = $e$ .

$f'' (x) = 4 (x^{2} e^{x} + e^{x} \frac{d}{d x} (x^{2})) + \frac{d}{d x} (18 x e^{x}) + \frac{d}{d x} (- 14 e^{x})$

Step 2.2.4

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 2$ .

$f'' (x) = 4 (x^{2} e^{x} + e^{x} (2 x)) + \frac{d}{d x} (18 x e^{x}) + \frac{d}{d x} (- 14 e^{x})$

Step 2.3

Evaluate $\frac{d}{d x} [18 x e^{x}]$ .

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Step 2.3.1

Since $18$ is constant with respect to $x$ , the derivative of $18 x e^{x}$ with respect to $x$ is $18 \frac{d}{d x} [x e^{x}]$ .

$f'' (x) = 4 (x^{2} e^{x} + e^{x} (2 x)) + 18 \frac{d}{d x} (x e^{x}) + \frac{d}{d x} (- 14 e^{x})$

Step 2.3.2

Differentiate using the Product Rule which states that $\frac{d}{d x} [f (x) g (x)]$ is $f (x) \frac{d}{d x} [g (x)] + g (x) \frac{d}{d x} [f (x)]$ where $f (x) = x$ and $g (x) = e^{x}$ .

$f'' (x) = 4 (x^{2} e^{x} + e^{x} (2 x)) + 18 (x \frac{d}{d x} (e^{x}) + e^{x} \frac{d}{d x} (x)) + \frac{d}{d x} (- 14 e^{x})$

Step 2.3.3

Differentiate using the Exponential Rule which states that $\frac{d}{d x} [a^{x}]$ is $a^{x} \ln (a)$ where $a$ = $e$ .

$f'' (x) = 4 (x^{2} e^{x} + e^{x} (2 x)) + 18 (x e^{x} + e^{x} \frac{d}{d x} (x)) + \frac{d}{d x} (- 14 e^{x})$

Step 2.3.4

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 1$ .

$f'' (x) = 4 (x^{2} e^{x} + e^{x} (2 x)) + 18 (x e^{x} + e^{x} \cdot 1) + \frac{d}{d x} (- 14 e^{x})$

Step 2.3.5

Multiply $e^{x}$ by $1$ .

$f'' (x) = 4 (x^{2} e^{x} + e^{x} (2 x)) + 18 (x e^{x} + e^{x}) + \frac{d}{d x} (- 14 e^{x})$

Step 2.4

Evaluate $\frac{d}{d x} [- 14 e^{x}]$ .

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Step 2.4.1

Since $- 14$ is constant with respect to $x$ , the derivative of $- 14 e^{x}$ with respect to $x$ is $- 14 \frac{d}{d x} [e^{x}]$ .

$f'' (x) = 4 (x^{2} e^{x} + e^{x} (2 x)) + 18 (x e^{x} + e^{x}) - 14 \frac{d}{d x} e^{x}$

Step 2.4.2

Differentiate using the Exponential Rule which states that $\frac{d}{d x} [a^{x}]$ is $a^{x} \ln (a)$ where $a$ = $e$ .

$f'' (x) = 4 (x^{2} e^{x} + e^{x} (2 x)) + 18 (x e^{x} + e^{x}) - 14 e^{x}$

Step 2.5

Simplify.

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Step 2.5.1

Apply the distributive property.

$f'' (x) = 4 (x^{2} e^{x}) + 4 (e^{x} (2 x)) + 18 (x e^{x} + e^{x}) - 14 e^{x}$

Step 2.5.2

Apply the distributive property.

$f'' (x) = 4 (x^{2} e^{x}) + 4 (e^{x} (2 x)) + 18 (x e^{x}) + 18 e^{x} - 14 e^{x}$

Step 2.5.3

Combine terms.

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Step 2.5.3.1

Multiply $2$ by $4$ .

$f'' (x) = 4 x^{2} e^{x} + 8 (e^{x} (x)) + 18 (x e^{x}) + 18 e^{x} - 14 e^{x}$

Step 2.5.3.2

Add $8 e^{x} x$ and $18 x e^{x}$ .

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Step 2.5.3.2.1

Move $e^{x}$ .

$f'' (x) = 4 x^{2} e^{x} + 8 x e^{x} + 18 x e^{x} + 18 e^{x} - 14 e^{x}$

Step 2.5.3.2.2

Add $8 x e^{x}$ and $18 x e^{x}$ .

$f'' (x) = 4 x^{2} e^{x} + 26 x e^{x} + 18 e^{x} - 14 e^{x}$

Step 2.5.3.3

Subtract $14 e^{x}$ from $18 e^{x}$ .

$f'' (x) = 4 x^{2} e^{x} + 26 x e^{x} + 4 e^{x}$

Step 2.5.4

Reorder terms.

$f'' (x) = 4 e^{x} x^{2} + 26 e^{x} x + 4 e^{x}$

Step 2.5.5

Reorder factors in $4 e^{x} x^{2} + 26 e^{x} x + 4 e^{x}$ .

$f'' (x) = 4 x^{2} e^{x} + 26 x e^{x} + 4 e^{x}$

Step 3

To find the local maximum and minimum values of the function, set the derivative equal to $0$ and solve.

$4 x^{2} e^{x} + 18 x e^{x} - 14 e^{x} = 0$

Step 4

Find the first derivative.

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Step 4.1

Find the first derivative.

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Step 4.1.1

By the Sum Rule, the derivative of $4 x^{2} e^{x} + 10 x e^{x} - 24 e^{x}$ with respect to $x$ is $\frac{d}{d x} [4 x^{2} e^{x}] + \frac{d}{d x} [10 x e^{x}] + \frac{d}{d x} [- 24 e^{x}]$ .

$\frac{d}{d x} [4 x^{2} e^{x}] + \frac{d}{d x} [10 x e^{x}] + \frac{d}{d x} [- 24 e^{x}]$

Step 4.1.2

Evaluate $\frac{d}{d x} [4 x^{2} e^{x}]$ .

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Step 4.1.2.1

Since $4$ is constant with respect to $x$ , the derivative of $4 x^{2} e^{x}$ with respect to $x$ is $4 \frac{d}{d x} [x^{2} e^{x}]$ .

$4 \frac{d}{d x} [x^{2} e^{x}] + \frac{d}{d x} [10 x e^{x}] + \frac{d}{d x} [- 24 e^{x}]$

Step 4.1.2.2

Differentiate using the Product Rule which states that $\frac{d}{d x} [f (x) g (x)]$ is $f (x) \frac{d}{d x} [g (x)] + g (x) \frac{d}{d x} [f (x)]$ where $f (x) = x^{2}$ and $g (x) = e^{x}$ .

$4 (x^{2} \frac{d}{d x} [e^{x}] + e^{x} \frac{d}{d x} [x^{2}]) + \frac{d}{d x} [10 x e^{x}] + \frac{d}{d x} [- 24 e^{x}]$

Step 4.1.2.3

Differentiate using the Exponential Rule which states that $\frac{d}{d x} [a^{x}]$ is $a^{x} \ln (a)$ where $a$ = $e$ .

$4 (x^{2} e^{x} + e^{x} \frac{d}{d x} [x^{2}]) + \frac{d}{d x} [10 x e^{x}] + \frac{d}{d x} [- 24 e^{x}]$

Step 4.1.2.4

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 2$ .

$4 (x^{2} e^{x} + e^{x} (2 x)) + \frac{d}{d x} [10 x e^{x}] + \frac{d}{d x} [- 24 e^{x}]$

Step 4.1.3

Evaluate $\frac{d}{d x} [10 x e^{x}]$ .

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Step 4.1.3.1

Since $10$ is constant with respect to $x$ , the derivative of $10 x e^{x}$ with respect to $x$ is $10 \frac{d}{d x} [x e^{x}]$ .

$4 (x^{2} e^{x} + e^{x} (2 x)) + 10 \frac{d}{d x} [x e^{x}] + \frac{d}{d x} [- 24 e^{x}]$

Step 4.1.3.2

Differentiate using the Product Rule which states that $\frac{d}{d x} [f (x) g (x)]$ is $f (x) \frac{d}{d x} [g (x)] + g (x) \frac{d}{d x} [f (x)]$ where $f (x) = x$ and $g (x) = e^{x}$ .

$4 (x^{2} e^{x} + e^{x} (2 x)) + 10 (x \frac{d}{d x} [e^{x}] + e^{x} \frac{d}{d x} [x]) + \frac{d}{d x} [- 24 e^{x}]$

Step 4.1.3.3

Differentiate using the Exponential Rule which states that $\frac{d}{d x} [a^{x}]$ is $a^{x} \ln (a)$ where $a$ = $e$ .

$4 (x^{2} e^{x} + e^{x} (2 x)) + 10 (x e^{x} + e^{x} \frac{d}{d x} [x]) + \frac{d}{d x} [- 24 e^{x}]$

Step 4.1.3.4

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 1$ .

$4 (x^{2} e^{x} + e^{x} (2 x)) + 10 (x e^{x} + e^{x} \cdot 1) + \frac{d}{d x} [- 24 e^{x}]$

Step 4.1.3.5

Multiply $e^{x}$ by $1$ .

$4 (x^{2} e^{x} + e^{x} (2 x)) + 10 (x e^{x} + e^{x}) + \frac{d}{d x} [- 24 e^{x}]$

Step 4.1.4

Evaluate $\frac{d}{d x} [- 24 e^{x}]$ .

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Step 4.1.4.1

Since $- 24$ is constant with respect to $x$ , the derivative of $- 24 e^{x}$ with respect to $x$ is $- 24 \frac{d}{d x} [e^{x}]$ .

$4 (x^{2} e^{x} + e^{x} (2 x)) + 10 (x e^{x} + e^{x}) - 24 \frac{d}{d x} [e^{x}]$

Step 4.1.4.2

Differentiate using the Exponential Rule which states that $\frac{d}{d x} [a^{x}]$ is $a^{x} \ln (a)$ where $a$ = $e$ .

$4 (x^{2} e^{x} + e^{x} (2 x)) + 10 (x e^{x} + e^{x}) - 24 e^{x}$

Step 4.1.5

Simplify.

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Step 4.1.5.1

Apply the distributive property.

$4 (x^{2} e^{x}) + 4 (e^{x} (2 x)) + 10 (x e^{x} + e^{x}) - 24 e^{x}$

Step 4.1.5.2

Apply the distributive property.

$4 (x^{2} e^{x}) + 4 (e^{x} (2 x)) + 10 (x e^{x}) + 10 e^{x} - 24 e^{x}$

Step 4.1.5.3

Combine terms.

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Step 4.1.5.3.1

Multiply $2$ by $4$ .

$4 x^{2} e^{x} + 8 (e^{x} (x)) + 10 (x e^{x}) + 10 e^{x} - 24 e^{x}$

Step 4.1.5.3.2

Add $8 e^{x} x$ and $10 x e^{x}$ .

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Step 4.1.5.3.2.1

Move $e^{x}$ .

$4 x^{2} e^{x} + 8 x e^{x} + 10 x e^{x} + 10 e^{x} - 24 e^{x}$

Step 4.1.5.3.2.2

Add $8 x e^{x}$ and $10 x e^{x}$ .

$4 x^{2} e^{x} + 18 x e^{x} + 10 e^{x} - 24 e^{x}$

Step 4.1.5.3.3

Subtract $24 e^{x}$ from $10 e^{x}$ .

$4 x^{2} e^{x} + 18 x e^{x} - 14 e^{x}$

Step 4.1.5.4

Reorder terms.

$4 e^{x} x^{2} + 18 e^{x} x - 14 e^{x}$

Step 4.1.5.5

Reorder factors in $4 e^{x} x^{2} + 18 e^{x} x - 14 e^{x}$ .

$f' (x) = 4 x^{2} e^{x} + 18 x e^{x} - 14 e^{x}$

Step 4.2

The first derivative of $f (x)$ with respect to $x$ is $4 x^{2} e^{x} + 18 x e^{x} - 14 e^{x}$ .

$4 x^{2} e^{x} + 18 x e^{x} - 14 e^{x}$

Step 5

Set the first derivative equal to $0$ then solve the equation $4 x^{2} e^{x} + 18 x e^{x} - 14 e^{x} = 0$ .

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Step 5.1

Set the first derivative equal to $0$ .

$4 x^{2} e^{x} + 18 x e^{x} - 14 e^{x} = 0$

Step 5.2

Factor $2 e^{x}$ out of $4 x^{2} e^{x} + 18 x e^{x} - 14 e^{x}$ .

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Step 5.2.1

Factor $2 e^{x}$ out of $4 x^{2} e^{x}$ .

$2 e^{x} (2 x^{2}) + 18 x e^{x} - 14 e^{x} = 0$

Step 5.2.2

Factor $2 e^{x}$ out of $18 x e^{x}$ .

$2 e^{x} (2 x^{2}) + 2 e^{x} (9 x) - 14 e^{x} = 0$

Step 5.2.3

Factor $2 e^{x}$ out of $- 14 e^{x}$ .

$2 e^{x} (2 x^{2}) + 2 e^{x} (9 x) + 2 e^{x} (- 7) = 0$

Step 5.2.4

Factor $2 e^{x}$ out of $2 e^{x} (2 x^{2}) + 2 e^{x} (9 x)$ .

$2 e^{x} (2 x^{2} + 9 x) + 2 e^{x} (- 7) = 0$

Step 5.2.5

Factor $2 e^{x}$ out of $2 e^{x} (2 x^{2} + 9 x) + 2 e^{x} (- 7)$ .

$2 e^{x} (2 x^{2} + 9 x - 7) = 0$

Step 5.3

If any individual factor on the left side of the equation is equal to $0$ , the entire expression will be equal to $0$ .

$e^{x} = 0$

$2 x^{2} + 9 x - 7 = 0$

Step 5.4

Set $e^{x}$ equal to $0$ and solve for $x$ .

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Step 5.4.1

Set $e^{x}$ equal to $0$ .

$e^{x} = 0$

Step 5.4.2

Solve $e^{x} = 0$ for $x$ .

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Step 5.4.2.1

Take the natural logarithm of both sides of the equation to remove the variable from the exponent.

$\ln (e^{x}) = \ln (0)$

Step 5.4.2.2

The equation cannot be solved because $\ln (0)$ is undefined.

Undefined

Step 5.4.2.3

There is no solution for $e^{x} = 0$

No solution

Step 5.5

Set $2 x^{2} + 9 x - 7$ equal to $0$ and solve for $x$ .

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Step 5.5.1

Set $2 x^{2} + 9 x - 7$ equal to $0$ .

$2 x^{2} + 9 x - 7 = 0$

Step 5.5.2

Solve $2 x^{2} + 9 x - 7 = 0$ for $x$ .

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Step 5.5.2.1

Use the quadratic formula to find the solutions.

$\frac{- b \pm \sqrt{b^{2} - 4 (a c)}}{2 a}$

Step 5.5.2.2

Substitute the values $a = 2$ , $b = 9$ , and $c = - 7$ into the quadratic formula and solve for $x$ .

$\frac{- 9 \pm \sqrt{9^{2} - 4 \cdot (2 \cdot - 7)}}{2 \cdot 2}$

Step 5.5.2.3

Simplify.

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Step 5.5.2.3.1

Simplify the numerator.

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Step 5.5.2.3.1.1

Raise $9$ to the power of $2$ .

$x = \frac{- 9 \pm \sqrt{81 - 4 \cdot 2 \cdot - 7}}{2 \cdot 2}$

Step 5.5.2.3.1.2

Multiply $- 4 \cdot 2 \cdot - 7$ .

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Step 5.5.2.3.1.2.1

Multiply $- 4$ by $2$ .

$x = \frac{- 9 \pm \sqrt{81 - 8 \cdot - 7}}{2 \cdot 2}$

Step 5.5.2.3.1.2.2

Multiply $- 8$ by $- 7$ .

$x = \frac{- 9 \pm \sqrt{81 + 56}}{2 \cdot 2}$

Step 5.5.2.3.1.3

Add $81$ and $56$ .

$x = \frac{- 9 \pm \sqrt{137}}{2 \cdot 2}$

Step 5.5.2.3.2

Multiply $2$ by $2$ .

$x = \frac{- 9 \pm \sqrt{137}}{4}$

Step 5.5.2.4

Simplify the expression to solve for the $+$ portion of the $\pm$ .

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Step 5.5.2.4.1

Simplify the numerator.

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Step 5.5.2.4.1.1

Raise $9$ to the power of $2$ .

$x = \frac{- 9 \pm \sqrt{81 - 4 \cdot 2 \cdot - 7}}{2 \cdot 2}$

Step 5.5.2.4.1.2

Multiply $- 4 \cdot 2 \cdot - 7$ .

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Step 5.5.2.4.1.2.1

Multiply $- 4$ by $2$ .

$x = \frac{- 9 \pm \sqrt{81 - 8 \cdot - 7}}{2 \cdot 2}$

Step 5.5.2.4.1.2.2

Multiply $- 8$ by $- 7$ .

$x = \frac{- 9 \pm \sqrt{81 + 56}}{2 \cdot 2}$

Step 5.5.2.4.1.3

Add $81$ and $56$ .

$x = \frac{- 9 \pm \sqrt{137}}{2 \cdot 2}$

Step 5.5.2.4.2

Multiply $2$ by $2$ .

$x = \frac{- 9 \pm \sqrt{137}}{4}$

Step 5.5.2.4.3

Change the $\pm$ to $+$ .

$x = \frac{- 9 + \sqrt{137}}{4}$

Step 5.5.2.4.4

Rewrite $- 9$ as $- 1 (9)$ .

$x = \frac{- 1 \cdot 9 + \sqrt{137}}{4}$

Step 5.5.2.4.5

Factor $- 1$ out of $\sqrt{137}$ .

$x = \frac{- 1 \cdot 9 - 1 (- \sqrt{137})}{4}$

Step 5.5.2.4.6

Factor $- 1$ out of $- 1 (9) - 1 (- \sqrt{137})$ .

$x = \frac{- 1 (9 - \sqrt{137})}{4}$

Step 5.5.2.4.7

Move the negative in front of the fraction.

$x = - \frac{9 - \sqrt{137}}{4}$

Step 5.5.2.5

Simplify the expression to solve for the $-$ portion of the $\pm$ .

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Step 5.5.2.5.1

Simplify the numerator.

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Step 5.5.2.5.1.1

Raise $9$ to the power of $2$ .

$x = \frac{- 9 \pm \sqrt{81 - 4 \cdot 2 \cdot - 7}}{2 \cdot 2}$

Step 5.5.2.5.1.2

Multiply $- 4 \cdot 2 \cdot - 7$ .

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Step 5.5.2.5.1.2.1

Multiply $- 4$ by $2$ .

$x = \frac{- 9 \pm \sqrt{81 - 8 \cdot - 7}}{2 \cdot 2}$

Step 5.5.2.5.1.2.2

Multiply $- 8$ by $- 7$ .

$x = \frac{- 9 \pm \sqrt{81 + 56}}{2 \cdot 2}$

Step 5.5.2.5.1.3

Add $81$ and $56$ .

$x = \frac{- 9 \pm \sqrt{137}}{2 \cdot 2}$

Step 5.5.2.5.2

Multiply $2$ by $2$ .

$x = \frac{- 9 \pm \sqrt{137}}{4}$

Step 5.5.2.5.3

Change the $\pm$ to $-$ .

$x = \frac{- 9 - \sqrt{137}}{4}$

Step 5.5.2.5.4

Rewrite $- 9$ as $- 1 (9)$ .

$x = \frac{- 1 \cdot 9 - \sqrt{137}}{4}$

Step 5.5.2.5.5

Factor $- 1$ out of $- \sqrt{137}$ .

$x = \frac{- 1 \cdot 9 - (\sqrt{137})}{4}$

Step 5.5.2.5.6

Factor $- 1$ out of $- 1 (9) - (\sqrt{137})$ .

$x = \frac{- 1 (9 + \sqrt{137})}{4}$

Step 5.5.2.5.7

Move the negative in front of the fraction.

$x = - \frac{9 + \sqrt{137}}{4}$

Step 5.5.2.6

The final answer is the combination of both solutions.

$x = - \frac{9 - \sqrt{137}}{4}, - \frac{9 + \sqrt{137}}{4}$

Step 5.6

The final solution is all the values that make $2 e^{x} (2 x^{2} + 9 x - 7) = 0$ true.

$x = - \frac{9 - \sqrt{137}}{4}, - \frac{9 + \sqrt{137}}{4}$

Step 6

Find the values where the derivative is undefined.

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Step 6.1

The domain of the expression is all real numbers except where the expression is undefined. In this case, there is no real number that makes the expression undefined.

Step 7

Critical points to evaluate.

$x = - \frac{9 - \sqrt{137}}{4}, - \frac{9 + \sqrt{137}}{4}$

Step 8

Evaluate the second derivative at $x = - \frac{9 - \sqrt{137}}{4}$ . If the second derivative is positive, then this is a local minimum. If it is negative, then this is a local maximum.

$4 {(- \frac{9 - \sqrt{137}}{4})}^{2} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9

Evaluate the second derivative.

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Step 9.1

Simplify each term.

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Step 9.1.1

Use the power rule ${(a b)}^{n} = a^{n} b^{n}$ to distribute the exponent.

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Step 9.1.1.1

Apply the product rule to $- \frac{9 - \sqrt{137}}{4}$ .

$4 ({(- 1)}^{2} {(\frac{9 - \sqrt{137}}{4})}^{2}) e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.1.2

Apply the product rule to $\frac{9 - \sqrt{137}}{4}$ .

$4 ({(- 1)}^{2} \frac{{(9 - \sqrt{137})}^{2}}{4^{2}}) e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.2

Raise $- 1$ to the power of $2$ .

$4 (1 \frac{{(9 - \sqrt{137})}^{2}}{4^{2}}) e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.3

Multiply $\frac{{(9 - \sqrt{137})}^{2}}{4^{2}}$ by $1$ .

$4 \frac{{(9 - \sqrt{137})}^{2}}{4^{2}} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.4

Raise $4$ to the power of $2$ .

$4 \frac{{(9 - \sqrt{137})}^{2}}{16} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.5

Cancel the common factor of $4$ .

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Step 9.1.5.1

Factor $4$ out of $16$ .

$4 \frac{{(9 - \sqrt{137})}^{2}}{4 (4)} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.5.2

Cancel the common factor.

$4 \frac{{(9 - \sqrt{137})}^{2}}{4 \cdot 4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.5.3

Rewrite the expression.

$\frac{{(9 - \sqrt{137})}^{2}}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.6

Rewrite ${(9 - \sqrt{137})}^{2}$ as $(9 - \sqrt{137}) (9 - \sqrt{137})$ .

$\frac{(9 - \sqrt{137}) (9 - \sqrt{137})}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.7

Expand $(9 - \sqrt{137}) (9 - \sqrt{137})$ using the FOIL Method.

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Step 9.1.7.1

Apply the distributive property.

$\frac{9 (9 - \sqrt{137}) - \sqrt{137} (9 - \sqrt{137})}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.7.2

Apply the distributive property.

$\frac{9 \cdot 9 + 9 (- \sqrt{137}) - \sqrt{137} (9 - \sqrt{137})}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.7.3

Apply the distributive property.

$\frac{9 \cdot 9 + 9 (- \sqrt{137}) - \sqrt{137} \cdot 9 - \sqrt{137} (- \sqrt{137})}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.8

Simplify and combine like terms.

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Step 9.1.8.1

Simplify each term.

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Step 9.1.8.1.1

Multiply $9$ by $9$ .

$\frac{81 + 9 (- \sqrt{137}) - \sqrt{137} \cdot 9 - \sqrt{137} (- \sqrt{137})}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.8.1.2

Multiply $- 1$ by $9$ .

$\frac{81 - 9 \sqrt{137} - \sqrt{137} \cdot 9 - \sqrt{137} (- \sqrt{137})}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.8.1.3

Multiply $9$ by $- 1$ .

$\frac{81 - 9 \sqrt{137} - 9 \sqrt{137} - \sqrt{137} (- \sqrt{137})}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.8.1.4

Multiply $- \sqrt{137} (- \sqrt{137})$ .

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Step 9.1.8.1.4.1

Multiply $- 1$ by $- 1$ .

$\frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + 1 \sqrt{137} \sqrt{137}}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.8.1.4.2

Multiply $\sqrt{137}$ by $1$ .

$\frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + \sqrt{137} \sqrt{137}}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.8.1.4.3

Raise $\sqrt{137}$ to the power of $1$ .

$\frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + {\sqrt{137}}^{1} \sqrt{137}}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.8.1.4.4

Raise $\sqrt{137}$ to the power of $1$ .

$\frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + {\sqrt{137}}^{1} {\sqrt{137}}^{1}}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.8.1.4.5

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$\frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + {\sqrt{137}}^{1 + 1}}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.8.1.4.6

Add $1$ and $1$ .

$\frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + {\sqrt{137}}^{2}}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.8.1.5

Rewrite ${\sqrt{137}}^{2}$ as $137$ .

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Step 9.1.8.1.5.1

Use $\sqrt[n]{a^{x}} = a^{\frac{x}{n}}$ to rewrite $\sqrt{137}$ as $137^{\frac{1}{2}}$ .

$\frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + {(137^{\frac{1}{2}})}^{2}}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.8.1.5.2

Apply the power rule and multiply exponents, ${(a^{m})}^{n} = a^{m n}$ .

$\frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + 137^{\frac{1}{2} \cdot 2}}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.8.1.5.3

Combine $\frac{1}{2}$ and $2$ .

$\frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + 137^{\frac{2}{2}}}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.8.1.5.4

Cancel the common factor of $2$ .

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Step 9.1.8.1.5.4.1

Cancel the common factor.

$\frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + 137^{\frac{2}{2}}}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.8.1.5.4.2

Rewrite the expression.

$\frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + 137^{1}}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.8.1.5.5

Evaluate the exponent.

$\frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + 137}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.8.2

Add $81$ and $137$ .

$\frac{218 - 9 \sqrt{137} - 9 \sqrt{137}}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.8.3

Subtract $9 \sqrt{137}$ from $- 9 \sqrt{137}$ .

$\frac{218 - 18 \sqrt{137}}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.9

Cancel the common factor of $218 - 18 \sqrt{137}$ and $4$ .

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Step 9.1.9.1

Factor $2$ out of $218$ .

$\frac{2 (109) - 18 \sqrt{137}}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.9.2

Factor $2$ out of $- 18 \sqrt{137}$ .

$\frac{2 (109) + 2 (- 9 \sqrt{137})}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.9.3

Factor $2$ out of $2 (109) + 2 (- 9 \sqrt{137})$ .

$\frac{2 (109 - 9 \sqrt{137})}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.9.4

Cancel the common factors.

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Step 9.1.9.4.1

Factor $2$ out of $4$ .

$\frac{2 (109 - 9 \sqrt{137})}{2 \cdot 2} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.9.4.2

Cancel the common factor.

$\frac{2 (109 - 9 \sqrt{137})}{2 \cdot 2} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.9.4.3

Rewrite the expression.

$\frac{109 - 9 \sqrt{137}}{2} e^{- \frac{9 - \sqrt{137}}{4}} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.10

Combine $\frac{109 - 9 \sqrt{137}}{2}$ and $e^{- \frac{9 - \sqrt{137}}{4}}$ .

$\frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} + 26 (- \frac{9 - \sqrt{137}}{4}) e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.11

Cancel the common factor of $2$ .

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Step 9.1.11.1

Move the leading negative in $- \frac{9 - \sqrt{137}}{4}$ into the numerator.

$\frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} + 26 \frac{- (9 - \sqrt{137})}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.11.2

Factor $2$ out of $26$ .

$\frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} + 2 (13) \frac{- (9 - \sqrt{137})}{4} e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.11.3

Factor $2$ out of $4$ .

$\frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} + 2 \cdot 13 \frac{- (9 - \sqrt{137})}{2 \cdot 2} e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.11.4

Cancel the common factor.

$\frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} + 2 \cdot 13 \frac{- (9 - \sqrt{137})}{2 \cdot 2} e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.11.5

Rewrite the expression.

$\frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} + 13 \frac{- (9 - \sqrt{137})}{2} e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.12

Combine $13$ and $\frac{- (9 - \sqrt{137})}{2}$ .

$\frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} + \frac{13 (- (9 - \sqrt{137}))}{2} e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.13

Multiply $- 1$ by $13$ .

$\frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} + \frac{- 13 (9 - \sqrt{137})}{2} e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.14

Move the negative in front of the fraction.

$\frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} - \frac{13 (9 - \sqrt{137})}{2} e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.15

Combine $e^{- \frac{9 - \sqrt{137}}{4}}$ and $\frac{13 (9 - \sqrt{137})}{2}$ .

$\frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} - \frac{e^{- \frac{9 - \sqrt{137}}{4}} (13 (9 - \sqrt{137}))}{2} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.1.16

Move $13$ to the left of $e^{- \frac{9 - \sqrt{137}}{4}}$ .

$\frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} - \frac{13 e^{- \frac{9 - \sqrt{137}}{4}} (9 - \sqrt{137})}{2} + 4 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 9.2

Combine the numerators over the common denominator.

$4 e^{- \frac{9 - \sqrt{137}}{4}} + \frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}} - 13 e^{- \frac{9 - \sqrt{137}}{4}} (9 - \sqrt{137})}{2}$

Step 9.3

Simplify each term.

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Step 9.3.1

Apply the distributive property.

$4 e^{- \frac{9 - \sqrt{137}}{4}} + \frac{109 e^{- \frac{9 - \sqrt{137}}{4}} - 9 \sqrt{137} e^{- \frac{9 - \sqrt{137}}{4}} - 13 e^{- \frac{9 - \sqrt{137}}{4}} (9 - \sqrt{137})}{2}$

Step 9.3.2

Apply the distributive property.

$4 e^{- \frac{9 - \sqrt{137}}{4}} + \frac{109 e^{- \frac{9 - \sqrt{137}}{4}} - 9 \sqrt{137} e^{- \frac{9 - \sqrt{137}}{4}} - 13 e^{- \frac{9 - \sqrt{137}}{4}} \cdot 9 - 13 e^{- \frac{9 - \sqrt{137}}{4}} (- \sqrt{137})}{2}$

Step 9.3.3

Multiply $9$ by $- 13$ .

$4 e^{- \frac{9 - \sqrt{137}}{4}} + \frac{109 e^{- \frac{9 - \sqrt{137}}{4}} - 9 \sqrt{137} e^{- \frac{9 - \sqrt{137}}{4}} - 117 e^{- \frac{9 - \sqrt{137}}{4}} - 13 e^{- \frac{9 - \sqrt{137}}{4}} (- \sqrt{137})}{2}$

Step 9.3.4

Multiply $- 1$ by $- 13$ .

$4 e^{- \frac{9 - \sqrt{137}}{4}} + \frac{109 e^{- \frac{9 - \sqrt{137}}{4}} - 9 \sqrt{137} e^{- \frac{9 - \sqrt{137}}{4}} - 117 e^{- \frac{9 - \sqrt{137}}{4}} + 13 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}}{2}$

Step 9.4

Simplify by adding terms.

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Step 9.4.1

Subtract $117 e^{- \frac{9 - \sqrt{137}}{4}}$ from $109 e^{- \frac{9 - \sqrt{137}}{4}}$ .

$4 e^{- \frac{9 - \sqrt{137}}{4}} + \frac{- 9 \sqrt{137} e^{- \frac{9 - \sqrt{137}}{4}} - 8 e^{- \frac{9 - \sqrt{137}}{4}} + 13 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}}{2}$

Step 9.4.2

Reorder the factors of $- 9 \sqrt{137} e^{- \frac{9 - \sqrt{137}}{4}}$ .

$4 e^{- \frac{9 - \sqrt{137}}{4}} + \frac{- 9 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} - 8 e^{- \frac{9 - \sqrt{137}}{4}} + 13 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}}{2}$

Step 9.4.3

Add $- 9 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}$ and $13 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}$ .

$4 e^{- \frac{9 - \sqrt{137}}{4}} + \frac{4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} - 8 e^{- \frac{9 - \sqrt{137}}{4}}}{2}$

Step 9.5

To write $4 e^{- \frac{9 - \sqrt{137}}{4}}$ as a fraction with a common denominator, multiply by $\frac{2}{2}$ .

$4 e^{- \frac{9 - \sqrt{137}}{4}} \cdot \frac{2}{2} + \frac{4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} - 8 e^{- \frac{9 - \sqrt{137}}{4}}}{2}$

Step 9.6

Combine fractions.

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Step 9.6.1

Combine $4 e^{- \frac{9 - \sqrt{137}}{4}}$ and $\frac{2}{2}$ .

$\frac{4 e^{- \frac{9 - \sqrt{137}}{4}} \cdot 2}{2} + \frac{4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} - 8 e^{- \frac{9 - \sqrt{137}}{4}}}{2}$

Step 9.6.2

Combine the numerators over the common denominator.

$\frac{4 e^{- \frac{9 - \sqrt{137}}{4}} \cdot 2 + 4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} - 8 e^{- \frac{9 - \sqrt{137}}{4}}}{2}$

Step 9.7

Simplify the numerator.

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Step 9.7.1

Multiply $2$ by $4$ .

$\frac{8 e^{- \frac{9 - \sqrt{137}}{4}} + 4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} - 8 e^{- \frac{9 - \sqrt{137}}{4}}}{2}$

Step 9.7.2

Subtract $8 e^{- \frac{9 - \sqrt{137}}{4}}$ from $8 e^{- \frac{9 - \sqrt{137}}{4}}$ .

$\frac{4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} + 0}{2}$

Step 9.7.3

Add $4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}$ and $0$ .

$\frac{4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}}{2}$

Step 9.8

Cancel the common factor of $4$ and $2$ .

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Step 9.8.1

Factor $2$ out of $4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}$ .

$\frac{2 (2 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137})}{2}$

Step 9.8.2

Cancel the common factors.

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Step 9.8.2.1

Factor $2$ out of $2$ .

$\frac{2 (2 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137})}{2 (1)}$

Step 9.8.2.2

Cancel the common factor.

$\frac{2 (2 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137})}{2 \cdot 1}$

Step 9.8.2.3

Rewrite the expression.

$\frac{2 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}}{1}$

Step 9.8.2.4

Divide $2 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}$ by $1$ .

$2 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}$

Step 10

$x = - \frac{9 - \sqrt{137}}{4}$ is a local minimum because the value of the second derivative is positive. This is referred to as the second derivative test.

$x = - \frac{9 - \sqrt{137}}{4}$ is a local minimum

Step 11

Find the y-value when $x = - \frac{9 - \sqrt{137}}{4}$ .

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Step 11.1

Replace the variable $x$ with $- \frac{9 - \sqrt{137}}{4}$ in the expression.

$f (- \frac{9 - \sqrt{137}}{4}) = 4 {(- \frac{9 - \sqrt{137}}{4})}^{2} e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2

Simplify the result.

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Step 11.2.1

Simplify each term.

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Step 11.2.1.1

Use the power rule ${(a b)}^{n} = a^{n} b^{n}$ to distribute the exponent.

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Step 11.2.1.1.1

Apply the product rule to $- \frac{9 - \sqrt{137}}{4}$ .

$f (- \frac{9 - \sqrt{137}}{4}) = 4 ({(- 1)}^{2} {(\frac{9 - \sqrt{137}}{4})}^{2}) e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.1.2

Apply the product rule to $\frac{9 - \sqrt{137}}{4}$ .

$f (- \frac{9 - \sqrt{137}}{4}) = 4 ({(- 1)}^{2} (\frac{{(9 - \sqrt{137})}^{2}}{4^{2}})) \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.2

Raise $- 1$ to the power of $2$ .

$f (- \frac{9 - \sqrt{137}}{4}) = 4 (1 (\frac{{(9 - \sqrt{137})}^{2}}{4^{2}})) \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.3

Multiply $\frac{{(9 - \sqrt{137})}^{2}}{4^{2}}$ by $1$ .

$f (- \frac{9 - \sqrt{137}}{4}) = 4 (\frac{{(9 - \sqrt{137})}^{2}}{4^{2}}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.4

Raise $4$ to the power of $2$ .

$f (- \frac{9 - \sqrt{137}}{4}) = 4 (\frac{{(9 - \sqrt{137})}^{2}}{16}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.5

Cancel the common factor of $4$ .

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Step 11.2.1.5.1

Factor $4$ out of $16$ .

$f (- \frac{9 - \sqrt{137}}{4}) = 4 (\frac{{(9 - \sqrt{137})}^{2}}{4 (4)}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.5.2

Cancel the common factor.

$f (- \frac{9 - \sqrt{137}}{4}) = 4 (\frac{{(9 - \sqrt{137})}^{2}}{4 \cdot 4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.5.3

Rewrite the expression.

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{{(9 - \sqrt{137})}^{2}}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.6

Rewrite ${(9 - \sqrt{137})}^{2}$ as $(9 - \sqrt{137}) (9 - \sqrt{137})$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{(9 - \sqrt{137}) (9 - \sqrt{137})}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.7

Expand $(9 - \sqrt{137}) (9 - \sqrt{137})$ using the FOIL Method.

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Step 11.2.1.7.1

Apply the distributive property.

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{9 (9 - \sqrt{137}) - \sqrt{137} (9 - \sqrt{137})}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.7.2

Apply the distributive property.

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{9 \cdot 9 + 9 (- \sqrt{137}) - \sqrt{137} (9 - \sqrt{137})}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.7.3

Apply the distributive property.

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{9 \cdot 9 + 9 (- \sqrt{137}) - \sqrt{137} \cdot 9 - \sqrt{137} (- \sqrt{137})}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.8

Simplify and combine like terms.

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Step 11.2.1.8.1

Simplify each term.

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Step 11.2.1.8.1.1

Multiply $9$ by $9$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{81 + 9 (- \sqrt{137}) - \sqrt{137} \cdot 9 - \sqrt{137} (- \sqrt{137})}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.8.1.2

Multiply $- 1$ by $9$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{81 - 9 \sqrt{137} - \sqrt{137} \cdot 9 - \sqrt{137} (- \sqrt{137})}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.8.1.3

Multiply $9$ by $- 1$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{81 - 9 \sqrt{137} - 9 \sqrt{137} - \sqrt{137} (- \sqrt{137})}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.8.1.4

Multiply $- \sqrt{137} (- \sqrt{137})$ .

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Step 11.2.1.8.1.4.1

Multiply $- 1$ by $- 1$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + 1 \sqrt{137} \sqrt{137}}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.8.1.4.2

Multiply $\sqrt{137}$ by $1$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + \sqrt{137} \sqrt{137}}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.8.1.4.3

Raise $\sqrt{137}$ to the power of $1$ .

Step 11.2.1.8.1.4.4

Raise $\sqrt{137}$ to the power of $1$ .

Step 11.2.1.8.1.4.5

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + {\sqrt{137}}^{1 + 1}}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.8.1.4.6

Add $1$ and $1$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + {\sqrt{137}}^{2}}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.8.1.5

Rewrite ${\sqrt{137}}^{2}$ as $137$ .

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Step 11.2.1.8.1.5.1

Use $\sqrt[n]{a^{x}} = a^{\frac{x}{n}}$ to rewrite $\sqrt{137}$ as $137^{\frac{1}{2}}$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + {(137^{\frac{1}{2}})}^{2}}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.8.1.5.2

Apply the power rule and multiply exponents, ${(a^{m})}^{n} = a^{m n}$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + 137^{\frac{1}{2} \cdot 2}}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.8.1.5.3

Combine $\frac{1}{2}$ and $2$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + 137^{\frac{2}{2}}}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.8.1.5.4

Cancel the common factor of $2$ .

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Step 11.2.1.8.1.5.4.1

Cancel the common factor.

Step 11.2.1.8.1.5.4.2

Rewrite the expression.

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{81 - 9 \sqrt{137} - 9 \sqrt{137} + 137}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.8.1.5.5

Evaluate the exponent.

Step 11.2.1.8.2

Add $81$ and $137$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{218 - 9 \sqrt{137} - 9 \sqrt{137}}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.8.3

Subtract $9 \sqrt{137}$ from $- 9 \sqrt{137}$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{218 - 18 \sqrt{137}}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.9

Cancel the common factor of $218 - 18 \sqrt{137}$ and $4$ .

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Step 11.2.1.9.1

Factor $2$ out of $218$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{2 (109) - 18 \sqrt{137}}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.9.2

Factor $2$ out of $- 18 \sqrt{137}$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{2 (109) + 2 (- 9 \sqrt{137})}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.9.3

Factor $2$ out of $2 (109) + 2 (- 9 \sqrt{137})$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{2 (109 - 9 \sqrt{137})}{4} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.9.4

Cancel the common factors.

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Step 11.2.1.9.4.1

Factor $2$ out of $4$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{2 (109 - 9 \sqrt{137})}{2 \cdot 2} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.9.4.2

Cancel the common factor.

Step 11.2.1.9.4.3

Rewrite the expression.

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{109 - 9 \sqrt{137}}{2} \cdot e^{- \frac{9 - \sqrt{137}}{4}} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.10

Combine $\frac{109 - 9 \sqrt{137}}{2}$ and $e^{- \frac{9 - \sqrt{137}}{4}}$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} + 10 (- \frac{9 - \sqrt{137}}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.11

Cancel the common factor of $2$ .

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Step 11.2.1.11.1

Move the leading negative in $- \frac{9 - \sqrt{137}}{4}$ into the numerator.

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} + 10 (\frac{- (9 - \sqrt{137})}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.11.2

Factor $2$ out of $10$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} + 2 (5) (\frac{- (9 - \sqrt{137})}{4}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.11.3

Factor $2$ out of $4$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} + 2 \cdot (5 (\frac{- (9 - \sqrt{137})}{2 \cdot 2})) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.11.4

Cancel the common factor.

Step 11.2.1.11.5

Rewrite the expression.

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} + 5 (\frac{- (9 - \sqrt{137})}{2}) \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.12

Combine $5$ and $\frac{- (9 - \sqrt{137})}{2}$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} + \frac{5 (- (9 - \sqrt{137}))}{2} \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.13

Multiply $- 1$ by $5$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} + \frac{- 5 (9 - \sqrt{137})}{2} \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.14

Move the negative in front of the fraction.

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} - \frac{5 (9 - \sqrt{137})}{2} \cdot e^{- \frac{9 - \sqrt{137}}{4}} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.15

Combine $e^{- \frac{9 - \sqrt{137}}{4}}$ and $\frac{5 (9 - \sqrt{137})}{2}$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} - \frac{e^{- \frac{9 - \sqrt{137}}{4}} (5 (9 - \sqrt{137}))}{2} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.1.16

Move $5$ to the left of $e^{- \frac{9 - \sqrt{137}}{4}}$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}}}{2} - \frac{5 e^{- \frac{9 - \sqrt{137}}{4}} (9 - \sqrt{137})}{2} - 24 e^{- \frac{9 - \sqrt{137}}{4}}$

Step 11.2.2

Combine the numerators over the common denominator.

$f (- \frac{9 - \sqrt{137}}{4}) = - 24 e^{- \frac{9 - \sqrt{137}}{4}} + \frac{(109 - 9 \sqrt{137}) e^{- \frac{9 - \sqrt{137}}{4}} - 5 e^{- \frac{9 - \sqrt{137}}{4}} (9 - \sqrt{137})}{2}$

Step 11.2.3

Simplify each term.

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Step 11.2.3.1

Apply the distributive property.

$f (- \frac{9 - \sqrt{137}}{4}) = - 24 e^{- \frac{9 - \sqrt{137}}{4}} + \frac{109 e^{- \frac{9 - \sqrt{137}}{4}} - 9 \sqrt{137} e^{- \frac{9 - \sqrt{137}}{4}} - 5 e^{- \frac{9 - \sqrt{137}}{4}} (9 - \sqrt{137})}{2}$

Step 11.2.3.2

Apply the distributive property.

Step 11.2.3.3

Multiply $9$ by $- 5$ .

$f (- \frac{9 - \sqrt{137}}{4}) = - 24 e^{- \frac{9 - \sqrt{137}}{4}} + \frac{109 e^{- \frac{9 - \sqrt{137}}{4}} - 9 \sqrt{137} e^{- \frac{9 - \sqrt{137}}{4}} - 45 e^{- \frac{9 - \sqrt{137}}{4}} - 5 e^{- \frac{9 - \sqrt{137}}{4}} (- \sqrt{137})}{2}$

Step 11.2.3.4

Multiply $- 1$ by $- 5$ .

Step 11.2.4

Simplify by adding terms.

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Step 11.2.4.1

Subtract $45 e^{- \frac{9 - \sqrt{137}}{4}}$ from $109 e^{- \frac{9 - \sqrt{137}}{4}}$ .

$f (- \frac{9 - \sqrt{137}}{4}) = - 24 e^{- \frac{9 - \sqrt{137}}{4}} + \frac{- 9 \sqrt{137} e^{- \frac{9 - \sqrt{137}}{4}} + 64 e^{- \frac{9 - \sqrt{137}}{4}} + 5 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}}{2}$

Step 11.2.4.2

Reorder the factors of $- 9 \sqrt{137} e^{- \frac{9 - \sqrt{137}}{4}}$ .

$f (- \frac{9 - \sqrt{137}}{4}) = - 24 e^{- \frac{9 - \sqrt{137}}{4}} + \frac{- 9 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} + 64 e^{- \frac{9 - \sqrt{137}}{4}} + 5 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}}{2}$

Step 11.2.4.3

Add $- 9 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}$ and $5 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}$ .

$f (- \frac{9 - \sqrt{137}}{4}) = - 24 e^{- \frac{9 - \sqrt{137}}{4}} + \frac{- 4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} + 64 e^{- \frac{9 - \sqrt{137}}{4}}}{2}$

Step 11.2.5

To write $- 24 e^{- \frac{9 - \sqrt{137}}{4}}$ as a fraction with a common denominator, multiply by $\frac{2}{2}$ .

$f (- \frac{9 - \sqrt{137}}{4}) = - 24 e^{- \frac{9 - \sqrt{137}}{4}} \cdot \frac{2}{2} + \frac{- 4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} + 64 e^{- \frac{9 - \sqrt{137}}{4}}}{2}$

Step 11.2.6

Combine fractions.

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Step 11.2.6.1

Combine $- 24 e^{- \frac{9 - \sqrt{137}}{4}}$ and $\frac{2}{2}$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{- 24 e^{- \frac{9 - \sqrt{137}}{4}} \cdot 2}{2} + \frac{- 4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} + 64 e^{- \frac{9 - \sqrt{137}}{4}}}{2}$

Step 11.2.6.2

Combine the numerators over the common denominator.

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{- 24 e^{- \frac{9 - \sqrt{137}}{4}} \cdot 2 - 4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} + 64 e^{- \frac{9 - \sqrt{137}}{4}}}{2}$

Step 11.2.7

Simplify the numerator.

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Step 11.2.7.1

Multiply $2$ by $- 24$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{- 48 e^{- \frac{9 - \sqrt{137}}{4}} - 4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} + 64 e^{- \frac{9 - \sqrt{137}}{4}}}{2}$

Step 11.2.7.2

Add $- 48 e^{- \frac{9 - \sqrt{137}}{4}}$ and $64 e^{- \frac{9 - \sqrt{137}}{4}}$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{- 4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} + 16 e^{- \frac{9 - \sqrt{137}}{4}}}{2}$

Step 11.2.8

Simplify with factoring out.

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Step 11.2.8.1

Factor $- 1$ out of $- 4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{- (4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}) + 16 e^{- \frac{9 - \sqrt{137}}{4}}}{2}$

Step 11.2.8.2

Factor $- 1$ out of $16 e^{- \frac{9 - \sqrt{137}}{4}}$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{- (4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}) - (- 16 e^{- \frac{9 - \sqrt{137}}{4}})}{2}$

Step 11.2.8.3

Factor $- 1$ out of $- (4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137}) - (- 16 e^{- \frac{9 - \sqrt{137}}{4}})$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{- (4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} - 16 e^{- \frac{9 - \sqrt{137}}{4}})}{2}$

Step 11.2.8.4

Simplify the expression.

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Step 11.2.8.4.1

Rewrite $- (4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} - 16 e^{- \frac{9 - \sqrt{137}}{4}})$ as $- 1 (4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} - 16 e^{- \frac{9 - \sqrt{137}}{4}})$ .

$f (- \frac{9 - \sqrt{137}}{4}) = \frac{- 1 (4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} - 16 e^{- \frac{9 - \sqrt{137}}{4}})}{2}$

Step 11.2.8.4.2

Move the negative in front of the fraction.

$f (- \frac{9 - \sqrt{137}}{4}) = - \frac{4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} - 16 e^{- \frac{9 - \sqrt{137}}{4}}}{2}$

Step 11.2.9

The final answer is $- \frac{4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} - 16 e^{- \frac{9 - \sqrt{137}}{4}}}{2}$ .

$y = - \frac{4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} - 16 e^{- \frac{9 - \sqrt{137}}{4}}}{2}$

Step 12

Evaluate the second derivative at $x = - \frac{9 + \sqrt{137}}{4}$ . If the second derivative is positive, then this is a local minimum. If it is negative, then this is a local maximum.

$4 {(- \frac{9 + \sqrt{137}}{4})}^{2} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13

Evaluate the second derivative.

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Step 13.1

Simplify each term.

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Step 13.1.1

Use the power rule ${(a b)}^{n} = a^{n} b^{n}$ to distribute the exponent.

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Step 13.1.1.1

Apply the product rule to $- \frac{9 + \sqrt{137}}{4}$ .

$4 ({(- 1)}^{2} {(\frac{9 + \sqrt{137}}{4})}^{2}) e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.1.2

Apply the product rule to $\frac{9 + \sqrt{137}}{4}$ .

$4 ({(- 1)}^{2} \frac{{(9 + \sqrt{137})}^{2}}{4^{2}}) e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.2

Raise $- 1$ to the power of $2$ .

$4 (1 \frac{{(9 + \sqrt{137})}^{2}}{4^{2}}) e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.3

Multiply $\frac{{(9 + \sqrt{137})}^{2}}{4^{2}}$ by $1$ .

$4 \frac{{(9 + \sqrt{137})}^{2}}{4^{2}} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.4

Raise $4$ to the power of $2$ .

$4 \frac{{(9 + \sqrt{137})}^{2}}{16} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.5

Cancel the common factor of $4$ .

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Step 13.1.5.1

Factor $4$ out of $16$ .

$4 \frac{{(9 + \sqrt{137})}^{2}}{4 (4)} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.5.2

Cancel the common factor.

$4 \frac{{(9 + \sqrt{137})}^{2}}{4 \cdot 4} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.5.3

Rewrite the expression.

$\frac{{(9 + \sqrt{137})}^{2}}{4} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.6

Rewrite ${(9 + \sqrt{137})}^{2}$ as $(9 + \sqrt{137}) (9 + \sqrt{137})$ .

$\frac{(9 + \sqrt{137}) (9 + \sqrt{137})}{4} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.7

Expand $(9 + \sqrt{137}) (9 + \sqrt{137})$ using the FOIL Method.

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Step 13.1.7.1

Apply the distributive property.

$\frac{9 (9 + \sqrt{137}) + \sqrt{137} (9 + \sqrt{137})}{4} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.7.2

Apply the distributive property.

$\frac{9 \cdot 9 + 9 \sqrt{137} + \sqrt{137} (9 + \sqrt{137})}{4} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.7.3

Apply the distributive property.

$\frac{9 \cdot 9 + 9 \sqrt{137} + \sqrt{137} \cdot 9 + \sqrt{137} \sqrt{137}}{4} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.8

Simplify and combine like terms.

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Step 13.1.8.1

Simplify each term.

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Step 13.1.8.1.1

Multiply $9$ by $9$ .

$\frac{81 + 9 \sqrt{137} + \sqrt{137} \cdot 9 + \sqrt{137} \sqrt{137}}{4} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.8.1.2

Move $9$ to the left of $\sqrt{137}$ .

$\frac{81 + 9 \sqrt{137} + 9 \cdot \sqrt{137} + \sqrt{137} \sqrt{137}}{4} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.8.1.3

Combine using the product rule for radicals.

$\frac{81 + 9 \sqrt{137} + 9 \sqrt{137} + \sqrt{137 \cdot 137}}{4} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.8.1.4

Multiply $137$ by $137$ .

$\frac{81 + 9 \sqrt{137} + 9 \sqrt{137} + \sqrt{18769}}{4} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.8.1.5

Rewrite $18769$ as $137^{2}$ .

$\frac{81 + 9 \sqrt{137} + 9 \sqrt{137} + \sqrt{137^{2}}}{4} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.8.1.6

Pull terms out from under the radical, assuming positive real numbers.

$\frac{81 + 9 \sqrt{137} + 9 \sqrt{137} + 137}{4} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.8.2

Add $81$ and $137$ .

$\frac{218 + 9 \sqrt{137} + 9 \sqrt{137}}{4} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.8.3

Add $9 \sqrt{137}$ and $9 \sqrt{137}$ .

$\frac{218 + 18 \sqrt{137}}{4} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.9

Cancel the common factor of $218 + 18 \sqrt{137}$ and $4$ .

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Step 13.1.9.1

Factor $2$ out of $218$ .

$\frac{2 (109) + 18 \sqrt{137}}{4} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.9.2

Factor $2$ out of $18 \sqrt{137}$ .

$\frac{2 (109) + 2 (9 \sqrt{137})}{4} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.9.3

Factor $2$ out of $2 (109) + 2 (9 \sqrt{137})$ .

$\frac{2 (109 + 9 \sqrt{137})}{4} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.9.4

Cancel the common factors.

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Step 13.1.9.4.1

Factor $2$ out of $4$ .

$\frac{2 (109 + 9 \sqrt{137})}{2 \cdot 2} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.9.4.2

Cancel the common factor.

$\frac{2 (109 + 9 \sqrt{137})}{2 \cdot 2} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.9.4.3

Rewrite the expression.

$\frac{109 + 9 \sqrt{137}}{2} e^{- \frac{9 + \sqrt{137}}{4}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.10

Combine $\frac{109 + 9 \sqrt{137}}{2}$ and $e^{- \frac{9 + \sqrt{137}}{4}}$ .

$\frac{(109 + 9 \sqrt{137}) e^{- \frac{9 + \sqrt{137}}{4}}}{2} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.11

Move $e^{- \frac{9 + \sqrt{137}}{4}}$ to the denominator using the negative exponent rule $b^{- n} = \frac{1}{b^{n}}$ .

$\frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} + 26 (- \frac{9 + \sqrt{137}}{4}) e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.12

Cancel the common factor of $2$ .

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Step 13.1.12.1

Move the leading negative in $- \frac{9 + \sqrt{137}}{4}$ into the numerator.

$\frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} + 26 \frac{- (9 + \sqrt{137})}{4} e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.12.2

Factor $2$ out of $26$ .

$\frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} + 2 (13) \frac{- (9 + \sqrt{137})}{4} e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.12.3

Factor $2$ out of $4$ .

$\frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} + 2 \cdot 13 \frac{- (9 + \sqrt{137})}{2 \cdot 2} e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.12.4

Cancel the common factor.

$\frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} + 2 \cdot 13 \frac{- (9 + \sqrt{137})}{2 \cdot 2} e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.12.5

Rewrite the expression.

$\frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} + 13 \frac{- (9 + \sqrt{137})}{2} e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.13

Combine $13$ and $\frac{- (9 + \sqrt{137})}{2}$ .

$\frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} + \frac{13 (- (9 + \sqrt{137}))}{2} e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.14

Multiply $- 1$ by $13$ .

$\frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} + \frac{- 13 (9 + \sqrt{137})}{2} e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.15

Move the negative in front of the fraction.

$\frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} - \frac{13 (9 + \sqrt{137})}{2} e^{- \frac{9 + \sqrt{137}}{4}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.16

Combine $e^{- \frac{9 + \sqrt{137}}{4}}$ and $\frac{13 (9 + \sqrt{137})}{2}$ .

$\frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} - \frac{e^{- \frac{9 + \sqrt{137}}{4}} (13 (9 + \sqrt{137}))}{2} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.1.17

Move $e^{- \frac{9 + \sqrt{137}}{4}}$ to the denominator using the negative exponent rule $b^{- n} = \frac{1}{b^{n}}$ .

$\frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} - \frac{13 (9 + \sqrt{137})}{2 e^{\frac{9 + \sqrt{137}}{4}}} + 4 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 13.2

Combine the numerators over the common denominator.

$4 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{109 + 9 \sqrt{137} - 13 (9 + \sqrt{137})}{2 e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.3

Simplify each term.

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Step 13.3.1

Apply the distributive property.

$4 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{109 + 9 \sqrt{137} - 13 \cdot 9 - 13 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.3.2

Multiply $- 13$ by $9$ .

$4 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{109 + 9 \sqrt{137} - 117 - 13 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.4

Simplify by adding terms.

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Step 13.4.1

Subtract $117$ from $109$ .

$4 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{- 8 + 9 \sqrt{137} - 13 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.4.2

Subtract $13 \sqrt{137}$ from $9 \sqrt{137}$ .

$4 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{- 8 - 4 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.5

Simplify each term.

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Step 13.5.1

Factor $2$ out of $- 8$ .

$4 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{2 \cdot - 4 - 4 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.5.2

Factor $2$ out of $- 4 \sqrt{137}$ .

$4 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{2 \cdot - 4 + 2 (- 2 \sqrt{137})}{2 e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.5.3

Factor $2$ out of $2 (- 4) + 2 (- 2 \sqrt{137})$ .

$4 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{2 (- 4 - 2 \sqrt{137})}{2 e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.5.4

Cancel the common factors.

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Step 13.5.4.1

Factor $2$ out of $2 e^{\frac{9 + \sqrt{137}}{4}}$ .

$4 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{2 (- 4 - 2 \sqrt{137})}{2 (e^{\frac{9 + \sqrt{137}}{4}})}$

Step 13.5.4.2

Cancel the common factor.

$4 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{2 (- 4 - 2 \sqrt{137})}{2 e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.5.4.3

Rewrite the expression.

$4 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{- 4 - 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.6

To write $4 e^{- \frac{9 + \sqrt{137}}{4}}$ as a fraction with a common denominator, multiply by $\frac{e^{\frac{9 + \sqrt{137}}{4}}}{e^{\frac{9 + \sqrt{137}}{4}}}$ .

$\frac{4 e^{- \frac{9 + \sqrt{137}}{4}} e^{\frac{9 + \sqrt{137}}{4}}}{e^{\frac{9 + \sqrt{137}}{4}}} + \frac{- 4 - 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.7

Combine the numerators over the common denominator.

$\frac{4 e^{- \frac{9 + \sqrt{137}}{4}} e^{\frac{9 + \sqrt{137}}{4}} - 4 - 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.8

Simplify the numerator.

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Step 13.8.1

Multiply $e^{- \frac{9 + \sqrt{137}}{4}}$ by $e^{\frac{9 + \sqrt{137}}{4}}$ by adding the exponents.

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Step 13.8.1.1

Move $e^{\frac{9 + \sqrt{137}}{4}}$ .

$\frac{4 (e^{\frac{9 + \sqrt{137}}{4}} e^{- \frac{9 + \sqrt{137}}{4}}) - 4 - 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.8.1.2

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$\frac{4 e^{\frac{9 + \sqrt{137}}{4} - \frac{9 + \sqrt{137}}{4}} - 4 - 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.8.1.3

Combine the numerators over the common denominator.

$\frac{4 e^{\frac{9 + \sqrt{137} - (9 + \sqrt{137})}{4}} - 4 - 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.8.1.4

Simplify each term.

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Step 13.8.1.4.1

Apply the distributive property.

$\frac{4 e^{\frac{9 + \sqrt{137} - 1 \cdot 9 - \sqrt{137}}{4}} - 4 - 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.8.1.4.2

Multiply $- 1$ by $9$ .

$\frac{4 e^{\frac{9 + \sqrt{137} - 9 - \sqrt{137}}{4}} - 4 - 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.8.1.5

Subtract $9$ from $9$ .

$\frac{4 e^{\frac{0 + \sqrt{137} - \sqrt{137}}{4}} - 4 - 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.8.1.6

Add $0$ and $\sqrt{137}$ .

$\frac{4 e^{\frac{\sqrt{137} - \sqrt{137}}{4}} - 4 - 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.8.1.7

Subtract $\sqrt{137}$ from $\sqrt{137}$ .

$\frac{4 e^{\frac{0}{4}} - 4 - 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.8.1.8

Divide $0$ by $4$ .

$\frac{4 e^{0} - 4 - 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.8.2

Simplify $4 e^{0}$ .

$\frac{4 - 4 - 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.8.3

Subtract $4$ from $4$ .

$\frac{0 - 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.8.4

Subtract $2 \sqrt{137}$ from $0$ .

$\frac{- 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 13.9

Move the negative in front of the fraction.

$- \frac{2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 14

$x = - \frac{9 + \sqrt{137}}{4}$ is a local maximum because the value of the second derivative is negative. This is referred to as the second derivative test.

$x = - \frac{9 + \sqrt{137}}{4}$ is a local maximum

Step 15

Find the y-value when $x = - \frac{9 + \sqrt{137}}{4}$ .

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Step 15.1

Replace the variable $x$ with $- \frac{9 + \sqrt{137}}{4}$ in the expression.

$f (- \frac{9 + \sqrt{137}}{4}) = 4 {(- \frac{9 + \sqrt{137}}{4})}^{2} e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2

Simplify the result.

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Step 15.2.1

Simplify each term.

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Step 15.2.1.1

Use the power rule ${(a b)}^{n} = a^{n} b^{n}$ to distribute the exponent.

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Step 15.2.1.1.1

Apply the product rule to $- \frac{9 + \sqrt{137}}{4}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = 4 ({(- 1)}^{2} {(\frac{9 + \sqrt{137}}{4})}^{2}) e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.1.2

Apply the product rule to $\frac{9 + \sqrt{137}}{4}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = 4 ({(- 1)}^{2} (\frac{{(9 + \sqrt{137})}^{2}}{4^{2}})) \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.2

Raise $- 1$ to the power of $2$ .

$f (- \frac{9 + \sqrt{137}}{4}) = 4 (1 (\frac{{(9 + \sqrt{137})}^{2}}{4^{2}})) \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.3

Multiply $\frac{{(9 + \sqrt{137})}^{2}}{4^{2}}$ by $1$ .

$f (- \frac{9 + \sqrt{137}}{4}) = 4 (\frac{{(9 + \sqrt{137})}^{2}}{4^{2}}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.4

Raise $4$ to the power of $2$ .

$f (- \frac{9 + \sqrt{137}}{4}) = 4 (\frac{{(9 + \sqrt{137})}^{2}}{16}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.5

Cancel the common factor of $4$ .

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Step 15.2.1.5.1

Factor $4$ out of $16$ .

$f (- \frac{9 + \sqrt{137}}{4}) = 4 (\frac{{(9 + \sqrt{137})}^{2}}{4 (4)}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.5.2

Cancel the common factor.

$f (- \frac{9 + \sqrt{137}}{4}) = 4 (\frac{{(9 + \sqrt{137})}^{2}}{4 \cdot 4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.5.3

Rewrite the expression.

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{{(9 + \sqrt{137})}^{2}}{4} \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.6

Rewrite ${(9 + \sqrt{137})}^{2}$ as $(9 + \sqrt{137}) (9 + \sqrt{137})$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{(9 + \sqrt{137}) (9 + \sqrt{137})}{4} \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.7

Expand $(9 + \sqrt{137}) (9 + \sqrt{137})$ using the FOIL Method.

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Step 15.2.1.7.1

Apply the distributive property.

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{9 (9 + \sqrt{137}) + \sqrt{137} (9 + \sqrt{137})}{4} \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.7.2

Apply the distributive property.

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{9 \cdot 9 + 9 \sqrt{137} + \sqrt{137} (9 + \sqrt{137})}{4} \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.7.3

Apply the distributive property.

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{9 \cdot 9 + 9 \sqrt{137} + \sqrt{137} \cdot 9 + \sqrt{137} \sqrt{137}}{4} \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.8

Simplify and combine like terms.

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Step 15.2.1.8.1

Simplify each term.

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Step 15.2.1.8.1.1

Multiply $9$ by $9$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{81 + 9 \sqrt{137} + \sqrt{137} \cdot 9 + \sqrt{137} \sqrt{137}}{4} \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.8.1.2

Move $9$ to the left of $\sqrt{137}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{81 + 9 \sqrt{137} + 9 \cdot \sqrt{137} + \sqrt{137} \sqrt{137}}{4} \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.8.1.3

Combine using the product rule for radicals.

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{81 + 9 \sqrt{137} + 9 \sqrt{137} + \sqrt{137 \cdot 137}}{4} \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.8.1.4

Multiply $137$ by $137$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{81 + 9 \sqrt{137} + 9 \sqrt{137} + \sqrt{18769}}{4} \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.8.1.5

Rewrite $18769$ as $137^{2}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{81 + 9 \sqrt{137} + 9 \sqrt{137} + \sqrt{137^{2}}}{4} \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.8.1.6

Pull terms out from under the radical, assuming positive real numbers.

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{81 + 9 \sqrt{137} + 9 \sqrt{137} + 137}{4} \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.8.2

Add $81$ and $137$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{218 + 9 \sqrt{137} + 9 \sqrt{137}}{4} \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.8.3

Add $9 \sqrt{137}$ and $9 \sqrt{137}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{218 + 18 \sqrt{137}}{4} \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.9

Cancel the common factor of $218 + 18 \sqrt{137}$ and $4$ .

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Step 15.2.1.9.1

Factor $2$ out of $218$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{2 (109) + 18 \sqrt{137}}{4} \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.9.2

Factor $2$ out of $18 \sqrt{137}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{2 (109) + 2 (9 \sqrt{137})}{4} \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.9.3

Factor $2$ out of $2 (109) + 2 (9 \sqrt{137})$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{2 (109 + 9 \sqrt{137})}{4} \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.9.4

Cancel the common factors.

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Step 15.2.1.9.4.1

Factor $2$ out of $4$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{2 (109 + 9 \sqrt{137})}{2 \cdot 2} \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.9.4.2

Cancel the common factor.

Step 15.2.1.9.4.3

Rewrite the expression.

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{109 + 9 \sqrt{137}}{2} \cdot e^{- \frac{9 + \sqrt{137}}{4}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.10

Combine $\frac{109 + 9 \sqrt{137}}{2}$ and $e^{- \frac{9 + \sqrt{137}}{4}}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{(109 + 9 \sqrt{137}) e^{- \frac{9 + \sqrt{137}}{4}}}{2} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.11

Move $e^{- \frac{9 + \sqrt{137}}{4}}$ to the denominator using the negative exponent rule $b^{- n} = \frac{1}{b^{n}}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} + 10 (- \frac{9 + \sqrt{137}}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.12

Cancel the common factor of $2$ .

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Step 15.2.1.12.1

Move the leading negative in $- \frac{9 + \sqrt{137}}{4}$ into the numerator.

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} + 10 (\frac{- (9 + \sqrt{137})}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.12.2

Factor $2$ out of $10$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} + 2 (5) (\frac{- (9 + \sqrt{137})}{4}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.12.3

Factor $2$ out of $4$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} + 2 \cdot (5 (\frac{- (9 + \sqrt{137})}{2 \cdot 2})) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.12.4

Cancel the common factor.

Step 15.2.1.12.5

Rewrite the expression.

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} + 5 (\frac{- (9 + \sqrt{137})}{2}) \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.13

Combine $5$ and $\frac{- (9 + \sqrt{137})}{2}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} + \frac{5 (- (9 + \sqrt{137}))}{2} \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.14

Multiply $- 1$ by $5$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} + \frac{- 5 (9 + \sqrt{137})}{2} \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.15

Move the negative in front of the fraction.

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} - \frac{5 (9 + \sqrt{137})}{2} \cdot e^{- \frac{9 + \sqrt{137}}{4}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.16

Combine $e^{- \frac{9 + \sqrt{137}}{4}}$ and $\frac{5 (9 + \sqrt{137})}{2}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} - \frac{e^{- \frac{9 + \sqrt{137}}{4}} (5 (9 + \sqrt{137}))}{2} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.1.17

Move $e^{- \frac{9 + \sqrt{137}}{4}}$ to the denominator using the negative exponent rule $b^{- n} = \frac{1}{b^{n}}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{109 + 9 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}} - \frac{5 (9 + \sqrt{137})}{2 e^{\frac{9 + \sqrt{137}}{4}}} - 24 e^{- \frac{9 + \sqrt{137}}{4}}$

Step 15.2.2

Combine the numerators over the common denominator.

$f (- \frac{9 + \sqrt{137}}{4}) = - 24 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{109 + 9 \sqrt{137} - 5 (9 + \sqrt{137})}{2 e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.3

Simplify each term.

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Step 15.2.3.1

Apply the distributive property.

$f (- \frac{9 + \sqrt{137}}{4}) = - 24 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{109 + 9 \sqrt{137} - 5 \cdot 9 - 5 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.3.2

Multiply $- 5$ by $9$ .

$f (- \frac{9 + \sqrt{137}}{4}) = - 24 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{109 + 9 \sqrt{137} - 45 - 5 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.4

Simplify by adding terms.

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Step 15.2.4.1

Subtract $45$ from $109$ .

$f (- \frac{9 + \sqrt{137}}{4}) = - 24 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{64 + 9 \sqrt{137} - 5 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.4.2

Subtract $5 \sqrt{137}$ from $9 \sqrt{137}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = - 24 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{64 + 4 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.5

Simplify each term.

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Step 15.2.5.1

Factor $2$ out of $64$ .

$f (- \frac{9 + \sqrt{137}}{4}) = - 24 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{2 \cdot 32 + 4 \sqrt{137}}{2 e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.5.2

Factor $2$ out of $4 \sqrt{137}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = - 24 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{2 \cdot 32 + 2 (2 \sqrt{137})}{2 e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.5.3

Factor $2$ out of $2 (32) + 2 (2 \sqrt{137})$ .

$f (- \frac{9 + \sqrt{137}}{4}) = - 24 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{2 (32 + 2 \sqrt{137})}{2 e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.5.4

Cancel the common factors.

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Step 15.2.5.4.1

Factor $2$ out of $2 e^{\frac{9 + \sqrt{137}}{4}}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = - 24 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{2 (32 + 2 \sqrt{137})}{2 (e^{\frac{9 + \sqrt{137}}{4}})}$

Step 15.2.5.4.2

Cancel the common factor.

$f (- \frac{9 + \sqrt{137}}{4}) = - 24 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{2 (32 + 2 \sqrt{137})}{2 e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.5.4.3

Rewrite the expression.

$f (- \frac{9 + \sqrt{137}}{4}) = - 24 e^{- \frac{9 + \sqrt{137}}{4}} + \frac{32 + 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.6

To write $- 24 e^{- \frac{9 + \sqrt{137}}{4}}$ as a fraction with a common denominator, multiply by $\frac{e^{\frac{9 + \sqrt{137}}{4}}}{e^{\frac{9 + \sqrt{137}}{4}}}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = - 24 e^{- \frac{9 + \sqrt{137}}{4}} \cdot \frac{e^{\frac{9 + \sqrt{137}}{4}}}{e^{\frac{9 + \sqrt{137}}{4}}} + \frac{32 + 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.7

Combine fractions.

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Step 15.2.7.1

Combine $- 24 e^{- \frac{9 + \sqrt{137}}{4}}$ and $\frac{e^{\frac{9 + \sqrt{137}}{4}}}{e^{\frac{9 + \sqrt{137}}{4}}}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{- 24 e^{- \frac{9 + \sqrt{137}}{4}} e^{\frac{9 + \sqrt{137}}{4}}}{e^{\frac{9 + \sqrt{137}}{4}}} + \frac{32 + 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.7.2

Combine the numerators over the common denominator.

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{- 24 e^{- \frac{9 + \sqrt{137}}{4}} e^{\frac{9 + \sqrt{137}}{4}} + 32 + 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.8

Simplify the numerator.

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Step 15.2.8.1

Multiply $e^{- \frac{9 + \sqrt{137}}{4}}$ by $e^{\frac{9 + \sqrt{137}}{4}}$ by adding the exponents.

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Step 15.2.8.1.1

Move $e^{\frac{9 + \sqrt{137}}{4}}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{- 24 (e^{\frac{9 + \sqrt{137}}{4}} e^{- \frac{9 + \sqrt{137}}{4}}) + 32 + 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.8.1.2

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{- 24 e^{\frac{9 + \sqrt{137}}{4} - \frac{9 + \sqrt{137}}{4}} + 32 + 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.8.1.3

Combine the numerators over the common denominator.

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{- 24 e^{\frac{9 + \sqrt{137} - (9 + \sqrt{137})}{4}} + 32 + 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.8.1.4

Simplify each term.

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Step 15.2.8.1.4.1

Apply the distributive property.

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{- 24 e^{\frac{9 + \sqrt{137} - 1 \cdot 9 - \sqrt{137}}{4}} + 32 + 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.8.1.4.2

Multiply $- 1$ by $9$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{- 24 e^{\frac{9 + \sqrt{137} - 9 - \sqrt{137}}{4}} + 32 + 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.8.1.5

Subtract $9$ from $9$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{- 24 e^{\frac{0 + \sqrt{137} - \sqrt{137}}{4}} + 32 + 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.8.1.6

Add $0$ and $\sqrt{137}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{- 24 e^{\frac{\sqrt{137} - \sqrt{137}}{4}} + 32 + 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.8.1.7

Subtract $\sqrt{137}$ from $\sqrt{137}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{- 24 e^{\frac{0}{4}} + 32 + 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.8.1.8

Divide $0$ by $4$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{- 24 e^{0} + 32 + 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.8.2

Simplify $- 24 e^{0}$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{- 24 + 32 + 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.8.3

Add $- 24$ and $32$ .

$f (- \frac{9 + \sqrt{137}}{4}) = \frac{8 + 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 15.2.9

The final answer is $\frac{8 + 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$ .

$y = \frac{8 + 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}}$

Step 16

These are the local extrema for $f (x) = 4 x^{2} e^{x} + 10 x e^{x} - 24 e^{x}$ .

$(- \frac{9 - \sqrt{137}}{4}, - \frac{4 e^{- \frac{9 - \sqrt{137}}{4}} \sqrt{137} - 16 e^{- \frac{9 - \sqrt{137}}{4}}}{2})$ is a local minima

$(- \frac{9 + \sqrt{137}}{4}, \frac{8 + 2 \sqrt{137}}{e^{\frac{9 + \sqrt{137}}{4}}})$ is a local maxima

Step 17