Calculus Examples

${(x^{4} - \frac{7}{x})}^{- 4}$

Step 1

Differentiate using the chain rule, which states that $\frac{d}{d x} [f (g (x))]$ is $f' (g (x)) g' (x)$ where $f (x) = x^{- 4}$ and $g (x) = x^{4} - \frac{7}{x}$ .

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Step 1.1

To apply the Chain Rule, set $u$ as $x^{4} - \frac{7}{x}$ .

$\frac{d}{d u} [u^{- 4}] \frac{d}{d x} [x^{4} - \frac{7}{x}]$

Step 1.2

Differentiate using the Power Rule which states that $\frac{d}{d u} [u^{n}]$ is $n u^{n - 1}$ where $n = - 4$ .

$- 4 u^{- 5} \frac{d}{d x} [x^{4} - \frac{7}{x}]$

Step 1.3

Replace all occurrences of $u$ with $x^{4} - \frac{7}{x}$ .

$- 4 {(x^{4} - \frac{7}{x})}^{- 5} \frac{d}{d x} [x^{4} - \frac{7}{x}]$

Step 2

Differentiate.

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Step 2.1

By the Sum Rule, the derivative of $x^{4} - \frac{7}{x}$ with respect to $x$ is $\frac{d}{d x} [x^{4}] + \frac{d}{d x} [- \frac{7}{x}]$ .

$- 4 {(x^{4} - \frac{7}{x})}^{- 5} (\frac{d}{d x} [x^{4}] + \frac{d}{d x} [- \frac{7}{x}])$

Step 2.2

Differentiate using the Power Rule which states that $\frac{d}{d x} [x^{n}]$ is $n x^{n - 1}$ where $n = 4$ .

$- 4 {(x^{4} - \frac{7}{x})}^{- 5} (4 x^{3} + \frac{d}{d x} [- \frac{7}{x}])$

Step 2.3

Since $- 7$ is constant with respect to $x$ , the derivative of $- \frac{7}{x}$ with respect to $x$ is $- 7 \frac{d}{d x} [\frac{1}{x}]$ .

$- 4 {(x^{4} - \frac{7}{x})}^{- 5} (4 x^{3} - 7 \frac{d}{d x} [\frac{1}{x}])$

Step 2.4

Rewrite $\frac{1}{x}$ as $x^{- 1}$ .

$- 4 {(x^{4} - \frac{7}{x})}^{- 5} (4 x^{3} - 7 \frac{d}{d x} [x^{- 1}])$

Step 2.5

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

$- 4 {(x^{4} - \frac{7}{x})}^{- 5} (4 x^{3} - 7 (- x^{- 2}))$

Step 2.6

Multiply $- 1$ by $- 7$ .

$- 4 {(x^{4} - \frac{7}{x})}^{- 5} (4 x^{3} + 7 x^{- 2})$

Step 3

Simplify.

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Step 3.1

Rewrite the expression using the negative exponent rule $b^{- n} = \frac{1}{b^{n}}$ .

$- 4 \frac{1}{{(x^{4} - \frac{7}{x})}^{5}} (4 x^{3} + 7 x^{- 2})$

Step 3.2

Rewrite the expression using the negative exponent rule $b^{- n} = \frac{1}{b^{n}}$ .

$- 4 \frac{1}{{(x^{4} - \frac{7}{x})}^{5}} (4 x^{3} + 7 \frac{1}{x^{2}})$

Step 3.3

Combine terms.

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Step 3.3.1

Combine $- 4$ and $\frac{1}{{(x^{4} - \frac{7}{x})}^{5}}$ .

$\frac{- 4}{{(x^{4} - \frac{7}{x})}^{5}} (4 x^{3} + 7 \frac{1}{x^{2}})$

Step 3.3.2

Move the negative in front of the fraction.

$- \frac{4}{{(x^{4} - \frac{7}{x})}^{5}} (4 x^{3} + 7 \frac{1}{x^{2}})$

Step 3.3.3

Combine $7$ and $\frac{1}{x^{2}}$ .

$- \frac{4}{{(x^{4} - \frac{7}{x})}^{5}} (4 x^{3} + \frac{7}{x^{2}})$

Step 3.4

Reorder the factors of $- \frac{4}{{(x^{4} - \frac{7}{x})}^{5}} (4 x^{3} + \frac{7}{x^{2}})$ .

$- (4 x^{3} + \frac{7}{x^{2}}) \frac{4}{{(x^{4} - \frac{7}{x})}^{5}}$

Step 3.5

Apply the distributive property.

$(- (4 x^{3}) - \frac{7}{x^{2}}) \frac{4}{{(x^{4} - \frac{7}{x})}^{5}}$

Step 3.6

Multiply $4$ by $- 1$ .

$(- 4 x^{3} - \frac{7}{x^{2}}) \frac{4}{{(x^{4} - \frac{7}{x})}^{5}}$

Step 3.7

Simplify the denominator.

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Step 3.7.1

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

$(- 4 x^{3} - \frac{7}{x^{2}}) \frac{4}{{(\frac{x^{4} x}{x} - \frac{7}{x})}^{5}}$

Step 3.7.2

Combine the numerators over the common denominator.

$(- 4 x^{3} - \frac{7}{x^{2}}) \frac{4}{{(\frac{x^{4} x - 7}{x})}^{5}}$

Step 3.7.3

Multiply $x^{4}$ by $x$ by adding the exponents.

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Step 3.7.3.1

Multiply $x^{4}$ by $x$ .

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Step 3.7.3.1.1

Raise $x$ to the power of $1$ .

$(- 4 x^{3} - \frac{7}{x^{2}}) \frac{4}{{(\frac{x^{4} x^{1} - 7}{x})}^{5}}$

Step 3.7.3.1.2

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

$(- 4 x^{3} - \frac{7}{x^{2}}) \frac{4}{{(\frac{x^{4 + 1} - 7}{x})}^{5}}$

Step 3.7.3.2

Add $4$ and $1$ .

$(- 4 x^{3} - \frac{7}{x^{2}}) \frac{4}{{(\frac{x^{5} - 7}{x})}^{5}}$

Step 3.7.4

Apply the product rule to $\frac{x^{5} - 7}{x}$ .

$(- 4 x^{3} - \frac{7}{x^{2}}) \frac{4}{\frac{{(x^{5} - 7)}^{5}}{x^{5}}}$

Step 3.8

Multiply the numerator by the reciprocal of the denominator.

$(- 4 x^{3} - \frac{7}{x^{2}}) (4 \frac{x^{5}}{{(x^{5} - 7)}^{5}})$

Step 3.9

Combine $4$ and $\frac{x^{5}}{{(x^{5} - 7)}^{5}}$ .

$(- 4 x^{3} - \frac{7}{x^{2}}) \frac{4 x^{5}}{{(x^{5} - 7)}^{5}}$

Step 3.10

Multiply $- 4 x^{3} - \frac{7}{x^{2}}$ by $\frac{4 x^{5}}{{(x^{5} - 7)}^{5}}$ .

$\frac{(- 4 x^{3} - \frac{7}{x^{2}}) (4 x^{5})}{{(x^{5} - 7)}^{5}}$

Step 3.11

Simplify the numerator.

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Step 3.11.1

To write $- 4 x^{3}$ as a fraction with a common denominator, multiply by $\frac{x^{2}}{x^{2}}$ .

$\frac{(- 4 x^{3} \cdot \frac{x^{2}}{x^{2}} - \frac{7}{x^{2}}) \cdot 4 x^{5}}{{(x^{5} - 7)}^{5}}$

Step 3.11.2

Combine $- 4 x^{3}$ and $\frac{x^{2}}{x^{2}}$ .

$\frac{(\frac{- 4 x^{3} x^{2}}{x^{2}} - \frac{7}{x^{2}}) \cdot 4 x^{5}}{{(x^{5} - 7)}^{5}}$

Step 3.11.3

Combine the numerators over the common denominator.

$\frac{\frac{- 4 x^{3} x^{2} - 7}{x^{2}} \cdot 4 x^{5}}{{(x^{5} - 7)}^{5}}$

Step 3.11.4

Multiply $x^{3}$ by $x^{2}$ by adding the exponents.

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Step 3.11.4.1

Move $x^{2}$ .

$\frac{\frac{- 4 (x^{2} x^{3}) - 7}{x^{2}} \cdot 4 x^{5}}{{(x^{5} - 7)}^{5}}$

Step 3.11.4.2

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

$\frac{\frac{- 4 x^{2 + 3} - 7}{x^{2}} \cdot 4 x^{5}}{{(x^{5} - 7)}^{5}}$

Step 3.11.4.3

Add $2$ and $3$ .

$\frac{\frac{- 4 x^{5} - 7}{x^{2}} \cdot 4 x^{5}}{{(x^{5} - 7)}^{5}}$

Step 3.11.5

Combine exponents.

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Step 3.11.5.1

Combine $\frac{- 4 x^{5} - 7}{x^{2}}$ and $4$ .

$\frac{\frac{(- 4 x^{5} - 7) \cdot 4}{x^{2}} x^{5}}{{(x^{5} - 7)}^{5}}$

Step 3.11.5.2

Combine $\frac{(- 4 x^{5} - 7) \cdot 4}{x^{2}}$ and $x^{5}$ .

$\frac{\frac{(- 4 x^{5} - 7) \cdot 4 x^{5}}{x^{2}}}{{(x^{5} - 7)}^{5}}$

Step 3.11.6

Reduce the expression by cancelling the common factors.

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Step 3.11.6.1

Reduce the expression $\frac{(- 4 x^{5} - 7) \cdot 4 x^{5}}{x^{2}}$ by cancelling the common factors.

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Step 3.11.6.1.1

Factor $x^{2}$ out of $(- 4 x^{5} - 7) \cdot 4 x^{5}$ .

$\frac{\frac{x^{2} ((- 4 x^{5} - 7) \cdot 4 x^{3})}{x^{2}}}{{(x^{5} - 7)}^{5}}$

Step 3.11.6.1.2

Multiply by $1$ .

$\frac{\frac{x^{2} ((- 4 x^{5} - 7) \cdot 4 x^{3})}{x^{2} \cdot 1}}{{(x^{5} - 7)}^{5}}$

Step 3.11.6.1.3

Cancel the common factor.

$\frac{\frac{x^{2} ((- 4 x^{5} - 7) \cdot 4 x^{3})}{x^{2} \cdot 1}}{{(x^{5} - 7)}^{5}}$

Step 3.11.6.1.4

Rewrite the expression.

$\frac{\frac{(- 4 x^{5} - 7) \cdot 4 x^{3}}{1}}{{(x^{5} - 7)}^{5}}$

Step 3.11.6.2

Divide $(- 4 x^{5} - 7) \cdot 4 x^{3}$ by $1$ .

$\frac{(- 4 x^{5} - 7) \cdot 4 x^{3}}{{(x^{5} - 7)}^{5}}$

Step 3.12

Move $4$ to the left of $- 4 x^{5} - 7$ .

$\frac{4 \cdot (- 4 x^{5} - 7) x^{3}}{{(x^{5} - 7)}^{5}}$

Step 3.13

Factor $- 1$ out of $- 4 x^{5}$ .

$\frac{4 (- (4 x^{5}) - 7) x^{3}}{{(x^{5} - 7)}^{5}}$

Step 3.14

Rewrite $- 7$ as $- 1 (7)$ .

$\frac{4 (- (4 x^{5}) - 1 (7)) x^{3}}{{(x^{5} - 7)}^{5}}$

Step 3.15

Factor $- 1$ out of $- (4 x^{5}) - 1 (7)$ .

$\frac{4 (- (4 x^{5} + 7)) x^{3}}{{(x^{5} - 7)}^{5}}$

Step 3.16

Rewrite $- (4 x^{5} + 7)$ as $- 1 (4 x^{5} + 7)$ .

$\frac{4 (- 1 (4 x^{5} + 7)) x^{3}}{{(x^{5} - 7)}^{5}}$

Step 3.17

Move the negative in front of the fraction.

$- \frac{(4 (4 x^{5} + 7)) x^{3}}{{(x^{5} - 7)}^{5}}$

Step 3.18

Reorder factors in $- \frac{(4 (4 x^{5} + 7)) x^{3}}{{(x^{5} - 7)}^{5}}$ .

$- \frac{(4) x^{3} (4 x^{5} + 7)}{{(x^{5} - 7)}^{5}}$