Calculus Examples

$y = \frac{e^{x} - e^{- x}}{e^{x} + e^{- x}}$

Step 1

Differentiate both sides of the equation.

$\frac{d}{d x} (y) = \frac{d}{d x} (\frac{e^{x} - e^{- x}}{e^{x} + e^{- x}})$

Step 2

The derivative of $y$ with respect to $x$ is $y'$ .

$y'$

Step 3

Differentiate the right side of the equation.

Tap for more steps...

Step 3.1

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

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

Step 3.2

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

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

Step 3.3

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

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

Step 3.4

Since $- 1$ is constant with respect to $x$ , the derivative of $- e^{- x}$ with respect to $x$ is $- \frac{d}{d x} [e^{- x}]$ .

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

Step 3.5

Differentiate using the chain rule, which states that $\frac{d}{d x} [f (g (x))]$ is $f' (g (x)) g' (x)$ where $f (x) = e^{x}$ and $g (x) = - x$ .

Tap for more steps...

Step 3.5.1

To apply the Chain Rule, set $u_{1}$ as $- x$ .

$\frac{(e^{x} + e^{- x}) (e^{x} - (\frac{d}{d u_{1}} [e^{u_{1}}] \frac{d}{d x} [- x])) - (e^{x} - e^{- x}) \frac{d}{d x} [e^{x} + e^{- x}]}{{(e^{x} + e^{- x})}^{2}}$

Step 3.5.2

Differentiate using the Exponential Rule which states that $\frac{d}{d u_{1}} [a^{u_{1}}]$ is $a^{u_{1}} \ln (a)$ where $a$ = $e$ .

$\frac{(e^{x} + e^{- x}) (e^{x} - (e^{u_{1}} \frac{d}{d x} [- x])) - (e^{x} - e^{- x}) \frac{d}{d x} [e^{x} + e^{- x}]}{{(e^{x} + e^{- x})}^{2}}$

Step 3.5.3

Replace all occurrences of $u_{1}$ with $- x$ .

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

Step 3.6

Differentiate.

Tap for more steps...

Step 3.6.1

Since $- 1$ is constant with respect to $x$ , the derivative of $- x$ with respect to $x$ is $- \frac{d}{d x} [x]$ .

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

Step 3.6.2

Multiply.

Tap for more steps...

Step 3.6.2.1

Multiply $- 1$ by $- 1$ .

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

Step 3.6.2.2

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

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

Step 3.6.3

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

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

Step 3.6.4

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

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

Step 3.7

Raise $e^{x} + e^{- x}$ to the power of $1$ .

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

Step 3.8

Raise $e^{x} + e^{- x}$ to the power of $1$ .

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

Step 3.9

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

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

Step 3.10

Differentiate using the Sum Rule.

Tap for more steps...

Step 3.10.1

Add $1$ and $1$ .

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

Step 3.10.2

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

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

Step 3.11

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

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

Step 3.12

Differentiate using the chain rule, which states that $\frac{d}{d x} [f (g (x))]$ is $f' (g (x)) g' (x)$ where $f (x) = e^{x}$ and $g (x) = - x$ .

Tap for more steps...

Step 3.12.1

To apply the Chain Rule, set $u_{2}$ as $- x$ .

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

Step 3.12.2

Differentiate using the Exponential Rule which states that $\frac{d}{d u_{2}} [a^{u_{2}}]$ is $a^{u_{2}} \ln (a)$ where $a$ = $e$ .

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

Step 3.12.3

Replace all occurrences of $u_{2}$ with $- x$ .

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

Step 3.13

Differentiate.

Tap for more steps...

Step 3.13.1

Since $- 1$ is constant with respect to $x$ , the derivative of $- x$ with respect to $x$ is $- \frac{d}{d x} [x]$ .

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

Step 3.13.2

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

$\frac{{(e^{x} + e^{- x})}^{2} - (e^{x} - e^{- x}) (e^{x} + e^{- x} (- 1 \cdot 1))}{{(e^{x} + e^{- x})}^{2}}$

Step 3.13.3

Simplify the expression.

Tap for more steps...

Step 3.13.3.1

Multiply $- 1$ by $1$ .

$\frac{{(e^{x} + e^{- x})}^{2} - (e^{x} - e^{- x}) (e^{x} + e^{- x} \cdot - 1)}{{(e^{x} + e^{- x})}^{2}}$

Step 3.13.3.2

Move $- 1$ to the left of $e^{- x}$ .

$\frac{{(e^{x} + e^{- x})}^{2} - (e^{x} - e^{- x}) (e^{x} - 1 \cdot e^{- x})}{{(e^{x} + e^{- x})}^{2}}$

Step 3.13.3.3

Rewrite $- 1 e^{- x}$ as $- e^{- x}$ .

$\frac{{(e^{x} + e^{- x})}^{2} - (e^{x} - e^{- x}) (e^{x} - e^{- x})}{{(e^{x} + e^{- x})}^{2}}$

Step 3.14

Raise $e^{x} - e^{- x}$ to the power of $1$ .

$\frac{{(e^{x} + e^{- x})}^{2} - ({(e^{x} - e^{- x})}^{1} (e^{x} - e^{- x}))}{{(e^{x} + e^{- x})}^{2}}$

Step 3.15

Raise $e^{x} - e^{- x}$ to the power of $1$ .

$\frac{{(e^{x} + e^{- x})}^{2} - ({(e^{x} - e^{- x})}^{1} {(e^{x} - e^{- x})}^{1})}{{(e^{x} + e^{- x})}^{2}}$

Step 3.16

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

$\frac{{(e^{x} + e^{- x})}^{2} - {(e^{x} - e^{- x})}^{1 + 1}}{{(e^{x} + e^{- x})}^{2}}$

Step 3.17

Add $1$ and $1$ .

$\frac{{(e^{x} + e^{- x})}^{2} - {(e^{x} - e^{- x})}^{2}}{{(e^{x} + e^{- x})}^{2}}$

Step 3.18

Simplify the numerator.

Tap for more steps...

Step 3.18.1

Since both terms are perfect squares, factor using the difference of squares formula, $a^{2} - b^{2} = (a + b) (a - b)$ where $a = e^{x} + e^{- x}$ and $b = e^{x} - e^{- x}$ .

$\frac{(e^{x} + e^{- x} + e^{x} - e^{- x}) (e^{x} + e^{- x} - (e^{x} - e^{- x}))}{{(e^{x} + e^{- x})}^{2}}$

Step 3.18.2

Simplify.

Tap for more steps...

Step 3.18.2.1

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

$\frac{(2 e^{x} + e^{- x} - e^{- x}) (e^{x} + e^{- x} - (e^{x} - e^{- x}))}{{(e^{x} + e^{- x})}^{2}}$

Step 3.18.2.2

Subtract $e^{- x}$ from $e^{- x}$ .

$\frac{(2 e^{x} + 0) (e^{x} + e^{- x} - (e^{x} - e^{- x}))}{{(e^{x} + e^{- x})}^{2}}$

Step 3.18.2.3

Add $2 e^{x}$ and $0$ .

$\frac{2 e^{x} (e^{x} + e^{- x} - (e^{x} - e^{- x}))}{{(e^{x} + e^{- x})}^{2}}$

Step 3.18.2.4

Apply the distributive property.

$\frac{2 e^{x} (e^{x} + e^{- x} - e^{x} - - e^{- x})}{{(e^{x} + e^{- x})}^{2}}$

Step 3.18.2.5

Multiply $- - e^{- x}$ .

Tap for more steps...

Step 3.18.2.5.1

Multiply $- 1$ by $- 1$ .

$\frac{2 e^{x} (e^{x} + e^{- x} - e^{x} + 1 e^{- x})}{{(e^{x} + e^{- x})}^{2}}$

Step 3.18.2.5.2

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

$\frac{2 e^{x} (e^{x} + e^{- x} - e^{x} + e^{- x})}{{(e^{x} + e^{- x})}^{2}}$

Step 3.18.2.6

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

$\frac{2 e^{x} (0 + e^{- x} + e^{- x})}{{(e^{x} + e^{- x})}^{2}}$

Step 3.18.2.7

Add $0$ and $e^{- x}$ .

$\frac{2 e^{x} (e^{- x} + e^{- x})}{{(e^{x} + e^{- x})}^{2}}$

Step 3.18.2.8

Add $e^{- x}$ and $e^{- x}$ .

$\frac{2 e^{x} \cdot 2 e^{- x}}{{(e^{x} + e^{- x})}^{2}}$

Step 3.18.2.9

Combine exponents.

Tap for more steps...

Step 3.18.2.9.1

Multiply $2$ by $2$ .

$\frac{4 e^{x} e^{- x}}{{(e^{x} + e^{- x})}^{2}}$

Step 3.18.2.9.2

Multiply $e^{x}$ by $e^{- x}$ by adding the exponents.

Tap for more steps...

Step 3.18.2.9.2.1

Move $e^{- x}$ .

$\frac{4 (e^{- x} e^{x})}{{(e^{x} + e^{- x})}^{2}}$

Step 3.18.2.9.2.2

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

$\frac{4 e^{- x + x}}{{(e^{x} + e^{- x})}^{2}}$

Step 3.18.2.9.2.3

Add $- x$ and $x$ .

$\frac{4 e^{0}}{{(e^{x} + e^{- x})}^{2}}$

Step 3.18.2.9.3

Simplify $4 e^{0}$ .

$\frac{4}{{(e^{x} + e^{- x})}^{2}}$

Step 4

Reform the equation by setting the left side equal to the right side.

$y' = \frac{4}{{(e^{x} + e^{- x})}^{2}}$

Step 5

Replace $y'$ with $\frac{d y}{d x}$ .

$\frac{d y}{d x} = \frac{4}{{(e^{x} + e^{- x})}^{2}}$