Calculus Examples

$lim_{x \to 0} \frac{\tan (x) - \sin (x)}{x^{3}}$

Step 1

Evaluate the limit of the numerator and the limit of the denominator.

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Step 1.1

Take the limit of the numerator and the limit of the denominator.

$\frac{lim_{x \to 0} \tan (x) - \sin (x)}{lim_{x \to 0} x^{3}}$

Step 1.2

Evaluate the limit of the numerator.

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Step 1.2.1

Split the limit using the Sum of Limits Rule on the limit as $x$ approaches $0$ .

$\frac{lim_{x \to 0} \tan (x) - lim_{x \to 0} \sin (x)}{lim_{x \to 0} x^{3}}$

Step 1.2.2

Move the limit inside the trig function because tangent is continuous.

$\frac{\tan (lim_{x \to 0} x) - lim_{x \to 0} \sin (x)}{lim_{x \to 0} x^{3}}$

Step 1.2.3

Move the limit inside the trig function because sine is continuous.

$\frac{\tan (lim_{x \to 0} x) - \sin (lim_{x \to 0} x)}{lim_{x \to 0} x^{3}}$

Step 1.2.4

Evaluate the limits by plugging in $0$ for all occurrences of $x$ .

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Step 1.2.4.1

Evaluate the limit of $x$ by plugging in $0$ for $x$ .

$\frac{\tan (0) - \sin (lim_{x \to 0} x)}{lim_{x \to 0} x^{3}}$

Step 1.2.4.2

Evaluate the limit of $x$ by plugging in $0$ for $x$ .

$\frac{\tan (0) - \sin (0)}{lim_{x \to 0} x^{3}}$

Step 1.2.5

Simplify the answer.

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Step 1.2.5.1

Simplify each term.

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Step 1.2.5.1.1

The exact value of $\tan (0)$ is $0$ .

$\frac{0 - \sin (0)}{lim_{x \to 0} x^{3}}$

Step 1.2.5.1.2

The exact value of $\sin (0)$ is $0$ .

$\frac{0 - 0}{lim_{x \to 0} x^{3}}$

Step 1.2.5.1.3

Multiply $- 1$ by $0$ .

$\frac{0 + 0}{lim_{x \to 0} x^{3}}$

Step 1.2.5.2

Add $0$ and $0$ .

$\frac{0}{lim_{x \to 0} x^{3}}$

Step 1.3

Evaluate the limit of the denominator.

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Step 1.3.1

Move the exponent $3$ from $x^{3}$ outside the limit using the Limits Power Rule.

$\frac{0}{{(lim_{x \to 0} x)}^{3}}$

Step 1.3.2

Evaluate the limit of $x$ by plugging in $0$ for $x$ .

$\frac{0}{0^{3}}$

Step 1.3.3

Raising $0$ to any positive power yields $0$ .

$\frac{0}{0}$

Step 1.3.4

The expression contains a division by $0$ . The expression is undefined.

Undefined

$\frac{0}{0}$

Step 1.4

The expression contains a division by $0$ . The expression is undefined.

Undefined

$\frac{0}{0}$

Step 2

Since $\frac{0}{0}$ is of indeterminate form, apply L'Hospital's Rule. L'Hospital's Rule states that the limit of a quotient of functions is equal to the limit of the quotient of their derivatives.

$lim_{x \to 0} \frac{\tan (x) - \sin (x)}{x^{3}} = lim_{x \to 0} \frac{\frac{d}{d x} [\tan (x) - \sin (x)]}{\frac{d}{d x} [x^{3}]}$

Step 3

Find the derivative of the numerator and denominator.

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Step 3.1

Differentiate the numerator and denominator.

$lim_{x \to 0} \frac{\frac{d}{d x} [\tan (x) - \sin (x)]}{\frac{d}{d x} [x^{3}]}$

Step 3.2

By the Sum Rule, the derivative of $\tan (x) - \sin (x)$ with respect to $x$ is $\frac{d}{d x} [\tan (x)] + \frac{d}{d x} [- \sin (x)]$ .

$lim_{x \to 0} \frac{\frac{d}{d x} [\tan (x)] + \frac{d}{d x} [- \sin (x)]}{\frac{d}{d x} [x^{3}]}$

Step 3.3

The derivative of $\tan (x)$ with respect to $x$ is $\sec^{2} (x)$ .

$lim_{x \to 0} \frac{\sec^{2} (x) + \frac{d}{d x} [- \sin (x)]}{\frac{d}{d x} [x^{3}]}$

Step 3.4

Evaluate $\frac{d}{d x} [- \sin (x)]$ .

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Step 3.4.1

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

$lim_{x \to 0} \frac{\sec^{2} (x) - \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x^{3}]}$

Step 3.4.2

The derivative of $\sin (x)$ with respect to $x$ is $\cos (x)$ .

$lim_{x \to 0} \frac{\sec^{2} (x) - \cos (x)}{\frac{d}{d x} [x^{3}]}$

Step 3.5

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 3$ .

$lim_{x \to 0} \frac{\sec^{2} (x) - \cos (x)}{3 x^{2}}$

Step 4

Move the term $\frac{1}{3}$ outside of the limit because it is constant with respect to $x$ .

$\frac{1}{3} lim_{x \to 0} \frac{\sec^{2} (x) - \cos (x)}{x^{2}}$

Step 5

Apply L'Hospital's rule.

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Step 5.1

Evaluate the limit of the numerator and the limit of the denominator.

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Step 5.1.1

Take the limit of the numerator and the limit of the denominator.

$\frac{1}{3} \cdot \frac{lim_{x \to 0} \sec^{2} (x) - \cos (x)}{lim_{x \to 0} x^{2}}$

Step 5.1.2

Evaluate the limit of the numerator.

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Step 5.1.2.1

Split the limit using the Sum of Limits Rule on the limit as $x$ approaches $0$ .

$\frac{1}{3} \cdot \frac{lim_{x \to 0} \sec^{2} (x) - lim_{x \to 0} \cos (x)}{lim_{x \to 0} x^{2}}$

Step 5.1.2.2

Move the exponent $2$ from $\sec^{2} (x)$ outside the limit using the Limits Power Rule.

$\frac{1}{3} \cdot \frac{{(lim_{x \to 0} \sec (x))}^{2} - lim_{x \to 0} \cos (x)}{lim_{x \to 0} x^{2}}$

Step 5.1.2.3

Move the limit inside the trig function because secant is continuous.

$\frac{1}{3} \cdot \frac{\sec^{2} (lim_{x \to 0} x) - lim_{x \to 0} \cos (x)}{lim_{x \to 0} x^{2}}$

Step 5.1.2.4

Move the limit inside the trig function because cosine is continuous.

$\frac{1}{3} \cdot \frac{\sec^{2} (lim_{x \to 0} x) - \cos (lim_{x \to 0} x)}{lim_{x \to 0} x^{2}}$

Step 5.1.2.5

Evaluate the limits by plugging in $0$ for all occurrences of $x$ .

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Step 5.1.2.5.1

Evaluate the limit of $x$ by plugging in $0$ for $x$ .

$\frac{1}{3} \cdot \frac{\sec^{2} (0) - \cos (lim_{x \to 0} x)}{lim_{x \to 0} x^{2}}$

Step 5.1.2.5.2

Evaluate the limit of $x$ by plugging in $0$ for $x$ .

$\frac{1}{3} \cdot \frac{\sec^{2} (0) - \cos (0)}{lim_{x \to 0} x^{2}}$

Step 5.1.2.6

Simplify the answer.

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Step 5.1.2.6.1

Simplify each term.

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Step 5.1.2.6.1.1

The exact value of $\sec (0)$ is $1$ .

$\frac{1}{3} \cdot \frac{1^{2} - \cos (0)}{lim_{x \to 0} x^{2}}$

Step 5.1.2.6.1.2

One to any power is one.

$\frac{1}{3} \cdot \frac{1 - \cos (0)}{lim_{x \to 0} x^{2}}$

Step 5.1.2.6.1.3

The exact value of $\cos (0)$ is $1$ .

$\frac{1}{3} \cdot \frac{1 - 1 \cdot 1}{lim_{x \to 0} x^{2}}$

Step 5.1.2.6.1.4

Multiply $- 1$ by $1$ .

$\frac{1}{3} \cdot \frac{1 - 1}{lim_{x \to 0} x^{2}}$

Step 5.1.2.6.2

Subtract $1$ from $1$ .

$\frac{1}{3} \cdot \frac{0}{lim_{x \to 0} x^{2}}$

Step 5.1.3

Evaluate the limit of the denominator.

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Step 5.1.3.1

Move the exponent $2$ from $x^{2}$ outside the limit using the Limits Power Rule.

$\frac{1}{3} \cdot \frac{0}{{(lim_{x \to 0} x)}^{2}}$

Step 5.1.3.2

Evaluate the limit of $x$ by plugging in $0$ for $x$ .

$\frac{1}{3} \cdot \frac{0}{0^{2}}$

Step 5.1.3.3

Raising $0$ to any positive power yields $0$ .

$\frac{1}{3} \cdot \frac{0}{0}$

Step 5.1.3.4

The expression contains a division by $0$ . The expression is undefined.

Undefined

$\frac{1}{3} \cdot \frac{0}{0}$

Step 5.1.4

The expression contains a division by $0$ . The expression is undefined.

Undefined

$\frac{1}{3} \cdot \frac{0}{0}$

Step 5.2

Since $\frac{0}{0}$ is of indeterminate form, apply L'Hospital's Rule. L'Hospital's Rule states that the limit of a quotient of functions is equal to the limit of the quotient of their derivatives.

$lim_{x \to 0} \frac{\sec^{2} (x) - \cos (x)}{x^{2}} = lim_{x \to 0} \frac{\frac{d}{d x} [\sec^{2} (x) - \cos (x)]}{\frac{d}{d x} [x^{2}]}$

Step 5.3

Find the derivative of the numerator and denominator.

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Step 5.3.1

Differentiate the numerator and denominator.

$\frac{1}{3} lim_{x \to 0} \frac{\frac{d}{d x} [\sec^{2} (x) - \cos (x)]}{\frac{d}{d x} [x^{2}]}$

Step 5.3.2

By the Sum Rule, the derivative of $\sec^{2} (x) - \cos (x)$ with respect to $x$ is $\frac{d}{d x} [\sec^{2} (x)] + \frac{d}{d x} [- \cos (x)]$ .

$\frac{1}{3} lim_{x \to 0} \frac{\frac{d}{d x} [\sec^{2} (x)] + \frac{d}{d x} [- \cos (x)]}{\frac{d}{d x} [x^{2}]}$

Step 5.3.3

Evaluate $\frac{d}{d x} [\sec^{2} (x)]$ .

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Step 5.3.3.1

Differentiate using the chain rule, which states that $\frac{d}{d x} [f (g (x))]$ is $f' (g (x)) g' (x)$ where $f (x) = x^{2}$ and $g (x) = \sec (x)$ .

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Step 5.3.3.1.1

To apply the Chain Rule, set $u$ as $\sec (x)$ .

$\frac{1}{3} lim_{x \to 0} \frac{\frac{d}{d u} [u^{2}] \frac{d}{d x} [\sec (x)] + \frac{d}{d x} [- \cos (x)]}{\frac{d}{d x} [x^{2}]}$

Step 5.3.3.1.2

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

$\frac{1}{3} lim_{x \to 0} \frac{2 u \frac{d}{d x} [\sec (x)] + \frac{d}{d x} [- \cos (x)]}{\frac{d}{d x} [x^{2}]}$

Step 5.3.3.1.3

Replace all occurrences of $u$ with $\sec (x)$ .

$\frac{1}{3} lim_{x \to 0} \frac{2 \sec (x) \frac{d}{d x} [\sec (x)] + \frac{d}{d x} [- \cos (x)]}{\frac{d}{d x} [x^{2}]}$

Step 5.3.3.2

The derivative of $\sec (x)$ with respect to $x$ is $\sec (x) \tan (x)$ .

$\frac{1}{3} lim_{x \to 0} \frac{2 \sec (x) \sec (x) \tan (x) + \frac{d}{d x} [- \cos (x)]}{\frac{d}{d x} [x^{2}]}$

Step 5.3.3.3

Raise $\sec (x)$ to the power of $1$ .

$\frac{1}{3} lim_{x \to 0} \frac{2 \sec^{1} (x) \sec (x) \tan (x) + \frac{d}{d x} [- \cos (x)]}{\frac{d}{d x} [x^{2}]}$

Step 5.3.3.4

Raise $\sec (x)$ to the power of $1$ .

$\frac{1}{3} lim_{x \to 0} \frac{2 \sec^{1} (x) \sec^{1} (x) \tan (x) + \frac{d}{d x} [- \cos (x)]}{\frac{d}{d x} [x^{2}]}$

Step 5.3.3.5

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

$\frac{1}{3} lim_{x \to 0} \frac{2 {\sec (x)}^{1 + 1} \tan (x) + \frac{d}{d x} [- \cos (x)]}{\frac{d}{d x} [x^{2}]}$

Step 5.3.3.6

Add $1$ and $1$ .

$\frac{1}{3} lim_{x \to 0} \frac{2 \sec^{2} (x) \tan (x) + \frac{d}{d x} [- \cos (x)]}{\frac{d}{d x} [x^{2}]}$

Step 5.3.4

Evaluate $\frac{d}{d x} [- \cos (x)]$ .

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Step 5.3.4.1

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

$\frac{1}{3} lim_{x \to 0} \frac{2 \sec^{2} (x) \tan (x) - \frac{d}{d x} [\cos (x)]}{\frac{d}{d x} [x^{2}]}$

Step 5.3.4.2

The derivative of $\cos (x)$ with respect to $x$ is $- \sin (x)$ .

$\frac{1}{3} lim_{x \to 0} \frac{2 \sec^{2} (x) \tan (x) - - 1 \sin (x)}{\frac{d}{d x} [x^{2}]}$

Step 5.3.4.3

Multiply $- 1$ by $- 1$ .

$\frac{1}{3} lim_{x \to 0} \frac{2 \sec^{2} (x) \tan (x) + 1 \sin (x)}{\frac{d}{d x} [x^{2}]}$

Step 5.3.4.4

Multiply $\sin (x)$ by $1$ .

$\frac{1}{3} lim_{x \to 0} \frac{2 \sec^{2} (x) \tan (x) + \sin (x)}{\frac{d}{d x} [x^{2}]}$

Step 5.3.5

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

$\frac{1}{3} lim_{x \to 0} \frac{2 \sec^{2} (x) \tan (x) + \sin (x)}{2 x}$

Step 6

Move the term $\frac{1}{2}$ outside of the limit because it is constant with respect to $x$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 \sec^{2} (x) \tan (x) + \sin (x)}{x}$

Step 7

Apply L'Hospital's rule.

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Step 7.1

Evaluate the limit of the numerator and the limit of the denominator.

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Step 7.1.1

Take the limit of the numerator and the limit of the denominator.

$\frac{1}{3} \cdot \frac{1}{2} \frac{lim_{x \to 0} 2 \sec^{2} (x) \tan (x) + \sin (x)}{lim_{x \to 0} x}$

Step 7.1.2

Evaluate the limit of the numerator.

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Step 7.1.2.1

Split the limit using the Sum of Limits Rule on the limit as $x$ approaches $0$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{lim_{x \to 0} 2 \sec^{2} (x) \tan (x) + lim_{x \to 0} \sin (x)}{lim_{x \to 0} x}$

Step 7.1.2.2

Move the term $2$ outside of the limit because it is constant with respect to $x$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{2 lim_{x \to 0} \sec^{2} (x) \tan (x) + lim_{x \to 0} \sin (x)}{lim_{x \to 0} x}$

Step 7.1.2.3

Split the limit using the Product of Limits Rule on the limit as $x$ approaches $0$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{2 lim_{x \to 0} \sec^{2} (x) \cdot lim_{x \to 0} \tan (x) + lim_{x \to 0} \sin (x)}{lim_{x \to 0} x}$

Step 7.1.2.4

Move the exponent $2$ from $\sec^{2} (x)$ outside the limit using the Limits Power Rule.

$\frac{1}{3} \cdot \frac{1}{2} \frac{2 {(lim_{x \to 0} \sec (x))}^{2} \cdot lim_{x \to 0} \tan (x) + lim_{x \to 0} \sin (x)}{lim_{x \to 0} x}$

Step 7.1.2.5

Move the limit inside the trig function because secant is continuous.

$\frac{1}{3} \cdot \frac{1}{2} \frac{2 \sec^{2} (lim_{x \to 0} x) \cdot lim_{x \to 0} \tan (x) + lim_{x \to 0} \sin (x)}{lim_{x \to 0} x}$

Step 7.1.2.6

Move the limit inside the trig function because tangent is continuous.

$\frac{1}{3} \cdot \frac{1}{2} \frac{2 \sec^{2} (lim_{x \to 0} x) \cdot \tan (lim_{x \to 0} x) + lim_{x \to 0} \sin (x)}{lim_{x \to 0} x}$

Step 7.1.2.7

Move the limit inside the trig function because sine is continuous.

$\frac{1}{3} \cdot \frac{1}{2} \frac{2 \sec^{2} (lim_{x \to 0} x) \cdot \tan (lim_{x \to 0} x) + \sin (lim_{x \to 0} x)}{lim_{x \to 0} x}$

Step 7.1.2.8

Evaluate the limits by plugging in $0$ for all occurrences of $x$ .

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Step 7.1.2.8.1

Evaluate the limit of $x$ by plugging in $0$ for $x$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{2 \sec^{2} (0) \cdot \tan (lim_{x \to 0} x) + \sin (lim_{x \to 0} x)}{lim_{x \to 0} x}$

Step 7.1.2.8.2

Evaluate the limit of $x$ by plugging in $0$ for $x$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{2 \sec^{2} (0) \cdot \tan (0) + \sin (lim_{x \to 0} x)}{lim_{x \to 0} x}$

Step 7.1.2.8.3

Evaluate the limit of $x$ by plugging in $0$ for $x$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{2 \sec^{2} (0) \cdot \tan (0) + \sin (0)}{lim_{x \to 0} x}$

Step 7.1.2.9

Simplify the answer.

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Step 7.1.2.9.1

Simplify each term.

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Step 7.1.2.9.1.1

The exact value of $\sec (0)$ is $1$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{2 \cdot 1^{2} \cdot \tan (0) + \sin (0)}{lim_{x \to 0} x}$

Step 7.1.2.9.1.2

One to any power is one.

$\frac{1}{3} \cdot \frac{1}{2} \frac{2 \cdot 1 \cdot \tan (0) + \sin (0)}{lim_{x \to 0} x}$

Step 7.1.2.9.1.3

Multiply $2$ by $1$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{2 \cdot \tan (0) + \sin (0)}{lim_{x \to 0} x}$

Step 7.1.2.9.1.4

The exact value of $\tan (0)$ is $0$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{2 \cdot 0 + \sin (0)}{lim_{x \to 0} x}$

Step 7.1.2.9.1.5

Multiply $2$ by $0$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{0 + \sin (0)}{lim_{x \to 0} x}$

Step 7.1.2.9.1.6

The exact value of $\sin (0)$ is $0$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{0 + 0}{lim_{x \to 0} x}$

Step 7.1.2.9.2

Add $0$ and $0$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{0}{lim_{x \to 0} x}$

Step 7.1.3

Evaluate the limit of $x$ by plugging in $0$ for $x$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{0}{0}$

Step 7.1.4

The expression contains a division by $0$ . The expression is undefined.

Undefined

$\frac{1}{3} \cdot \frac{1}{2} \frac{0}{0}$

Step 7.2

Since $\frac{0}{0}$ is of indeterminate form, apply L'Hospital's Rule. L'Hospital's Rule states that the limit of a quotient of functions is equal to the limit of the quotient of their derivatives.

$lim_{x \to 0} \frac{2 \sec^{2} (x) \tan (x) + \sin (x)}{x} = lim_{x \to 0} \frac{\frac{d}{d x} [2 \sec^{2} (x) \tan (x) + \sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3

Find the derivative of the numerator and denominator.

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Step 7.3.1

Differentiate the numerator and denominator.

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{\frac{d}{d x} [2 \sec^{2} (x) \tan (x) + \sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.2

By the Sum Rule, the derivative of $2 \sec^{2} (x) \tan (x) + \sin (x)$ with respect to $x$ is $\frac{d}{d x} [2 \sec^{2} (x) \tan (x)] + \frac{d}{d x} [\sin (x)]$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{\frac{d}{d x} [2 \sec^{2} (x) \tan (x)] + \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.3

Evaluate $\frac{d}{d x} [2 \sec^{2} (x) \tan (x)]$ .

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Step 7.3.3.1

Since $2$ is constant with respect to $x$ , the derivative of $2 \sec^{2} (x) \tan (x)$ with respect to $x$ is $2 \frac{d}{d x} [\sec^{2} (x) \tan (x)]$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 \frac{d}{d x} [\sec^{2} (x) \tan (x)] + \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.3.2

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 $f (x) = \sec^{2} (x)$ and $g (x) = \tan (x)$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 (\sec^{2} (x) \frac{d}{d x} [\tan (x)] + \tan (x) \frac{d}{d x} [\sec^{2} (x)]) + \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.3.3

The derivative of $\tan (x)$ with respect to $x$ is $\sec^{2} (x)$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 (\sec^{2} (x) \sec^{2} (x) + \tan (x) \frac{d}{d x} [\sec^{2} (x)]) + \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.3.4

Differentiate using the chain rule, which states that $\frac{d}{d x} [f (g (x))]$ is $f' (g (x)) g' (x)$ where $f (x) = x^{2}$ and $g (x) = \sec (x)$ .

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Step 7.3.3.4.1

To apply the Chain Rule, set $u$ as $\sec (x)$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 (\sec^{2} (x) \sec^{2} (x) + \tan (x) \frac{d}{d u} [u^{2}] \frac{d}{d x} [\sec (x)]) + \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.3.4.2

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

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 (\sec^{2} (x) \sec^{2} (x) + \tan (x) \cdot 2 u \frac{d}{d x} [\sec (x)]) + \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.3.4.3

Replace all occurrences of $u$ with $\sec (x)$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 (\sec^{2} (x) \sec^{2} (x) + \tan (x) \cdot 2 \sec (x) \frac{d}{d x} [\sec (x)]) + \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.3.5

The derivative of $\sec (x)$ with respect to $x$ is $\sec (x) \tan (x)$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 (\sec^{2} (x) \sec^{2} (x) + \tan (x) \cdot 2 \sec (x) \sec (x) \tan (x)) + \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.3.6

Multiply $\sec^{2} (x)$ by $\sec^{2} (x)$ by adding the exponents.

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Step 7.3.3.6.1

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

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 ({\sec (x)}^{2 + 2} + \tan (x) \cdot 2 \sec (x) \sec (x) \tan (x)) + \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.3.6.2

Add $2$ and $2$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 (\sec^{4} (x) + \tan (x) \cdot 2 \sec (x) \sec (x) \tan (x)) + \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.3.7

Raise $\sec (x)$ to the power of $1$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 (\sec^{4} (x) + \tan (x) \cdot 2 \sec^{1} (x) \sec (x) \tan (x)) + \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.3.8

Raise $\sec (x)$ to the power of $1$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 (\sec^{4} (x) + \tan (x) \cdot 2 \sec^{1} (x) \sec^{1} (x) \tan (x)) + \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.3.9

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

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 (\sec^{4} (x) + \tan (x) \cdot 2 {\sec (x)}^{1 + 1} \tan (x)) + \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.3.10

Add $1$ and $1$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 (\sec^{4} (x) + \tan (x) \cdot 2 \sec^{2} (x) \tan (x)) + \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.3.11

Raise $\tan (x)$ to the power of $1$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 (\sec^{4} (x) + 2 \sec^{2} (x) \tan^{1} (x) \tan (x)) + \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.3.12

Raise $\tan (x)$ to the power of $1$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 (\sec^{4} (x) + 2 \sec^{2} (x) \tan^{1} (x) \tan^{1} (x)) + \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.3.13

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

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 (\sec^{4} (x) + 2 \sec^{2} (x) {\tan (x)}^{1 + 1}) + \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.3.14

Add $1$ and $1$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 (\sec^{4} (x) + 2 \sec^{2} (x) \tan^{2} (x)) + \frac{d}{d x} [\sin (x)]}{\frac{d}{d x} [x]}$

Step 7.3.4

The derivative of $\sin (x)$ with respect to $x$ is $\cos (x)$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 (\sec^{4} (x) + 2 \sec^{2} (x) \tan^{2} (x)) + \cos (x)}{\frac{d}{d x} [x]}$

Step 7.3.5

Simplify.

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Step 7.3.5.1

Apply the distributive property.

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 \sec^{4} (x) + 2 \cdot 2 \sec^{2} (x) \tan^{2} (x) + \cos (x)}{\frac{d}{d x} [x]}$

Step 7.3.5.2

Multiply $2$ by $2$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{2 \sec^{4} (x) + 4 \sec^{2} (x) \tan^{2} (x) + \cos (x)}{\frac{d}{d x} [x]}$

Step 7.3.5.3

Reorder terms.

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{4 \sec^{2} (x) \tan^{2} (x) + 2 \sec^{4} (x) + \cos (x)}{\frac{d}{d x} [x]}$

Step 7.3.5.4

Simplify each term.

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Step 7.3.5.4.1

Rewrite $\sec (x)$ in terms of sines and cosines.

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{4 {(\frac{1}{\cos (x)})}^{2} \tan^{2} (x) + 2 \sec^{4} (x) + \cos (x)}{\frac{d}{d x} [x]}$

Step 7.3.5.4.2

Apply the product rule to $\frac{1}{\cos (x)}$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{4 \frac{1^{2}}{\cos^{2} (x)} \tan^{2} (x) + 2 \sec^{4} (x) + \cos (x)}{\frac{d}{d x} [x]}$

Step 7.3.5.4.3

One to any power is one.

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{4 \frac{1}{\cos^{2} (x)} \tan^{2} (x) + 2 \sec^{4} (x) + \cos (x)}{\frac{d}{d x} [x]}$

Step 7.3.5.4.4

Combine $4$ and $\frac{1}{\cos^{2} (x)}$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{\frac{4}{\cos^{2} (x)} \tan^{2} (x) + 2 \sec^{4} (x) + \cos (x)}{\frac{d}{d x} [x]}$

Step 7.3.5.4.5

Rewrite $\tan (x)$ in terms of sines and cosines.

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{\frac{4}{\cos^{2} (x)} {(\frac{\sin (x)}{\cos (x)})}^{2} + 2 \sec^{4} (x) + \cos (x)}{\frac{d}{d x} [x]}$

Step 7.3.5.4.6

Apply the product rule to $\frac{\sin (x)}{\cos (x)}$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{\frac{4}{\cos^{2} (x)} \cdot \frac{\sin^{2} (x)}{\cos^{2} (x)} + 2 \sec^{4} (x) + \cos (x)}{\frac{d}{d x} [x]}$

Step 7.3.5.4.7

Combine.

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{\frac{4 \sin^{2} (x)}{\cos^{2} (x) \cos^{2} (x)} + 2 \sec^{4} (x) + \cos (x)}{\frac{d}{d x} [x]}$

Step 7.3.5.4.8

Multiply $\cos^{2} (x)$ by $\cos^{2} (x)$ by adding the exponents.

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Step 7.3.5.4.8.1

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

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{\frac{4 \sin^{2} (x)}{{\cos (x)}^{2 + 2}} + 2 \sec^{4} (x) + \cos (x)}{\frac{d}{d x} [x]}$

Step 7.3.5.4.8.2

Add $2$ and $2$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{\frac{4 \sin^{2} (x)}{\cos^{4} (x)} + 2 \sec^{4} (x) + \cos (x)}{\frac{d}{d x} [x]}$

Step 7.3.5.4.9

Rewrite $\sec (x)$ in terms of sines and cosines.

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{\frac{4 \sin^{2} (x)}{\cos^{4} (x)} + 2 {(\frac{1}{\cos (x)})}^{4} + \cos (x)}{\frac{d}{d x} [x]}$

Step 7.3.5.4.10

Apply the product rule to $\frac{1}{\cos (x)}$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{\frac{4 \sin^{2} (x)}{\cos^{4} (x)} + 2 \frac{1^{4}}{\cos^{4} (x)} + \cos (x)}{\frac{d}{d x} [x]}$

Step 7.3.5.4.11

One to any power is one.

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{\frac{4 \sin^{2} (x)}{\cos^{4} (x)} + 2 \frac{1}{\cos^{4} (x)} + \cos (x)}{\frac{d}{d x} [x]}$

Step 7.3.5.4.12

Combine $2$ and $\frac{1}{\cos^{4} (x)}$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{\frac{4 \sin^{2} (x)}{\cos^{4} (x)} + \frac{2}{\cos^{4} (x)} + \cos (x)}{\frac{d}{d x} [x]}$

Step 7.3.6

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

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{\frac{4 \sin^{2} (x)}{\cos^{4} (x)} + \frac{2}{\cos^{4} (x)} + \cos (x)}{1}$

Step 7.4

Combine terms.

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Step 7.4.1

Combine the numerators over the common denominator.

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{\frac{4 \sin^{2} (x) + 2}{\cos^{4} (x)} + \cos (x)}{1}$

Step 7.4.2

To write $\cos (x)$ as a fraction with a common denominator, multiply by $\frac{\cos^{4} (x)}{\cos^{4} (x)}$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{\frac{4 \sin^{2} (x) + 2}{\cos^{4} (x)} + \frac{\cos (x) \cos^{4} (x)}{\cos^{4} (x)}}{1}$

Step 7.4.3

Combine the numerators over the common denominator.

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{\frac{4 \sin^{2} (x) + 2 + \cos (x) \cos^{4} (x)}{\cos^{4} (x)}}{1}$

Step 7.5

Divide $\frac{4 \sin^{2} (x) + 2 + \cos (x) \cos^{4} (x)}{\cos^{4} (x)}$ by $1$ .

$\frac{1}{3} \cdot \frac{1}{2} lim_{x \to 0} \frac{4 \sin^{2} (x) + 2 + \cos (x) \cos^{4} (x)}{\cos^{4} (x)}$

Step 8

Evaluate the limit.

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Step 8.1

Split the limit using the Limits Quotient Rule on the limit as $x$ approaches $0$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{lim_{x \to 0} 4 \sin^{2} (x) + 2 + \cos (x) \cos^{4} (x)}{lim_{x \to 0} \cos^{4} (x)}$

Step 8.2

Split the limit using the Sum of Limits Rule on the limit as $x$ approaches $0$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{lim_{x \to 0} 4 \sin^{2} (x) + lim_{x \to 0} 2 + lim_{x \to 0} \cos (x) \cos^{4} (x)}{lim_{x \to 0} \cos^{4} (x)}$

Step 8.3

Move the term $4$ outside of the limit because it is constant with respect to $x$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{4 lim_{x \to 0} \sin^{2} (x) + lim_{x \to 0} 2 + lim_{x \to 0} \cos (x) \cos^{4} (x)}{lim_{x \to 0} \cos^{4} (x)}$

Step 8.4

Move the exponent $2$ from $\sin^{2} (x)$ outside the limit using the Limits Power Rule.

$\frac{1}{3} \cdot \frac{1}{2} \frac{4 {(lim_{x \to 0} \sin (x))}^{2} + lim_{x \to 0} 2 + lim_{x \to 0} \cos (x) \cos^{4} (x)}{lim_{x \to 0} \cos^{4} (x)}$

Step 8.5

Move the limit inside the trig function because sine is continuous.

$\frac{1}{3} \cdot \frac{1}{2} \frac{4 \sin^{2} (lim_{x \to 0} x) + lim_{x \to 0} 2 + lim_{x \to 0} \cos (x) \cos^{4} (x)}{lim_{x \to 0} \cos^{4} (x)}$

Step 8.6

Evaluate the limit of $2$ which is constant as $x$ approaches $0$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{4 \sin^{2} (lim_{x \to 0} x) + 2 + lim_{x \to 0} \cos (x) \cos^{4} (x)}{lim_{x \to 0} \cos^{4} (x)}$

Step 8.7

Split the limit using the Product of Limits Rule on the limit as $x$ approaches $0$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{4 \sin^{2} (lim_{x \to 0} x) + 2 + lim_{x \to 0} \cos (x) \cdot lim_{x \to 0} \cos^{4} (x)}{lim_{x \to 0} \cos^{4} (x)}$

Step 8.8

Move the limit inside the trig function because cosine is continuous.

$\frac{1}{3} \cdot \frac{1}{2} \frac{4 \sin^{2} (lim_{x \to 0} x) + 2 + \cos (lim_{x \to 0} x) \cdot lim_{x \to 0} \cos^{4} (x)}{lim_{x \to 0} \cos^{4} (x)}$

Step 8.9

Move the exponent $4$ from $\cos^{4} (x)$ outside the limit using the Limits Power Rule.

$\frac{1}{3} \cdot \frac{1}{2} \frac{4 \sin^{2} (lim_{x \to 0} x) + 2 + \cos (lim_{x \to 0} x) \cdot {(lim_{x \to 0} \cos (x))}^{4}}{lim_{x \to 0} \cos^{4} (x)}$

Step 8.10

Move the limit inside the trig function because cosine is continuous.

$\frac{1}{3} \cdot \frac{1}{2} \frac{4 \sin^{2} (lim_{x \to 0} x) + 2 + \cos (lim_{x \to 0} x) \cdot \cos^{4} (lim_{x \to 0} x)}{lim_{x \to 0} \cos^{4} (x)}$

Step 8.11

Move the exponent $4$ from $\cos^{4} (x)$ outside the limit using the Limits Power Rule.

$\frac{1}{3} \cdot \frac{1}{2} \frac{4 \sin^{2} (lim_{x \to 0} x) + 2 + \cos (lim_{x \to 0} x) \cdot \cos^{4} (lim_{x \to 0} x)}{{(lim_{x \to 0} \cos (x))}^{4}}$

Step 8.12

Move the limit inside the trig function because cosine is continuous.

$\frac{1}{3} \cdot \frac{1}{2} \frac{4 \sin^{2} (lim_{x \to 0} x) + 2 + \cos (lim_{x \to 0} x) \cdot \cos^{4} (lim_{x \to 0} x)}{\cos^{4} (lim_{x \to 0} x)}$

Step 9

Evaluate the limits by plugging in $0$ for all occurrences of $x$ .

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Step 9.1

Evaluate the limit of $x$ by plugging in $0$ for $x$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{4 \sin^{2} (0) + 2 + \cos (lim_{x \to 0} x) \cdot \cos^{4} (lim_{x \to 0} x)}{\cos^{4} (lim_{x \to 0} x)}$

Step 9.2

Evaluate the limit of $x$ by plugging in $0$ for $x$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{4 \sin^{2} (0) + 2 + \cos (0) \cdot \cos^{4} (lim_{x \to 0} x)}{\cos^{4} (lim_{x \to 0} x)}$

Step 9.3

Evaluate the limit of $x$ by plugging in $0$ for $x$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{4 \sin^{2} (0) + 2 + \cos (0) \cdot \cos^{4} (0)}{\cos^{4} (lim_{x \to 0} x)}$

Step 9.4

Evaluate the limit of $x$ by plugging in $0$ for $x$ .

$\frac{1}{3} \cdot \frac{1}{2} \frac{4 \sin^{2} (0) + 2 + \cos (0) \cdot \cos^{4} (0)}{\cos^{4} (0)}$

Step 10

Simplify the answer.

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Step 10.1

Multiply $\frac{1}{3} \cdot \frac{1}{2}$ .

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Step 10.1.1

Multiply $\frac{1}{3}$ by $\frac{1}{2}$ .

$\frac{1}{3 \cdot 2} \cdot \frac{4 \sin^{2} (0) + 2 + \cos (0) \cdot \cos^{4} (0)}{\cos^{4} (0)}$

Step 10.1.2

Multiply $3$ by $2$ .

$\frac{1}{6} \cdot \frac{4 \sin^{2} (0) + 2 + \cos (0) \cdot \cos^{4} (0)}{\cos^{4} (0)}$

Step 10.2

Simplify the numerator.

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Step 10.2.1

The exact value of $\sin (0)$ is $0$ .

$\frac{1}{6} \cdot \frac{4 \cdot 0^{2} + 2 + \cos (0) \cdot \cos^{4} (0)}{\cos^{4} (0)}$

Step 10.2.2

Raising $0$ to any positive power yields $0$ .

$\frac{1}{6} \cdot \frac{4 \cdot 0 + 2 + \cos (0) \cdot \cos^{4} (0)}{\cos^{4} (0)}$

Step 10.2.3

Multiply $4$ by $0$ .

$\frac{1}{6} \cdot \frac{0 + 2 + \cos (0) \cdot \cos^{4} (0)}{\cos^{4} (0)}$

Step 10.2.4

Multiply $\cos (0)$ by $\cos^{4} (0)$ by adding the exponents.

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Step 10.2.4.1

Multiply $\cos (0)$ by $\cos^{4} (0)$ .

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Step 10.2.4.1.1

Raise $\cos (0)$ to the power of $1$ .

$\frac{1}{6} \cdot \frac{0 + 2 + \cos^{1} (0) \cdot \cos^{4} (0)}{\cos^{4} (0)}$

Step 10.2.4.1.2

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

$\frac{1}{6} \cdot \frac{0 + 2 + {\cos (0)}^{1 + 4}}{\cos^{4} (0)}$

Step 10.2.4.2

Add $1$ and $4$ .

$\frac{1}{6} \cdot \frac{0 + 2 + \cos^{5} (0)}{\cos^{4} (0)}$

Step 10.2.5

The exact value of $\cos (0)$ is $1$ .

$\frac{1}{6} \cdot \frac{0 + 2 + 1^{5}}{\cos^{4} (0)}$

Step 10.2.6

One to any power is one.

$\frac{1}{6} \cdot \frac{0 + 2 + 1}{\cos^{4} (0)}$

Step 10.2.7

Add $0$ and $2$ .

$\frac{1}{6} \cdot \frac{2 + 1}{\cos^{4} (0)}$

Step 10.2.8

Add $2$ and $1$ .

$\frac{1}{6} \cdot \frac{3}{\cos^{4} (0)}$

Step 10.3

Simplify the denominator.

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Step 10.3.1

The exact value of $\cos (0)$ is $1$ .

$\frac{1}{6} \cdot \frac{3}{1^{4}}$

Step 10.3.2

One to any power is one.

$\frac{1}{6} \cdot \frac{3}{1}$

Step 10.4

Divide $3$ by $1$ .

$\frac{1}{6} \cdot 3$

Step 10.5

Cancel the common factor of $3$ .

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Step 10.5.1

Factor $3$ out of $6$ .

$\frac{1}{3 (2)} \cdot 3$

Step 10.5.2

Cancel the common factor.

$\frac{1}{3 \cdot 2} \cdot 3$

Step 10.5.3

Rewrite the expression.

$\frac{1}{2}$