Calculus Examples

$\frac{(x + 4) (x + 1)}{4 x - 1}$

Step 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 $f (x) = (x + 4) (x + 1)$ and $g (x) = 4 x - 1$ .

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

Step 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 $f (x) = x + 4$ and $g (x) = x + 1$ .

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

Step 3

Differentiate.

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Step 3.1

By the Sum Rule, the derivative of $x + 1$ with respect to $x$ is $\frac{d}{d x} [x] + \frac{d}{d x} [1]$ .

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

Step 3.2

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

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

Step 3.3

Since $1$ is constant with respect to $x$ , the derivative of $1$ with respect to $x$ is $0$ .

$\frac{(4 x - 1) ((x + 4) (1 + 0) + (x + 1) \frac{d}{d x} [x + 4]) - (x + 4) (x + 1) \frac{d}{d x} [4 x - 1]}{{(4 x - 1)}^{2}}$

Step 3.4

Simplify the expression.

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Step 3.4.1

Add $1$ and $0$ .

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

Step 3.4.2

Multiply $x + 4$ by $1$ .

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

Step 3.5

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

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

Step 3.6

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

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

Step 3.7

Since $4$ is constant with respect to $x$ , the derivative of $4$ with respect to $x$ is $0$ .

$\frac{(4 x - 1) (x + 4 + (x + 1) (1 + 0)) - (x + 4) (x + 1) \frac{d}{d x} [4 x - 1]}{{(4 x - 1)}^{2}}$

Step 3.8

Simplify by adding terms.

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Step 3.8.1

Add $1$ and $0$ .

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

Step 3.8.2

Multiply $x + 1$ by $1$ .

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

Step 3.8.3

Add $x$ and $x$ .

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

Step 3.8.4

Add $4$ and $1$ .

$\frac{(4 x - 1) (2 x + 5) - (x + 4) (x + 1) \frac{d}{d x} [4 x - 1]}{{(4 x - 1)}^{2}}$

Step 3.9

By the Sum Rule, the derivative of $4 x - 1$ with respect to $x$ is $\frac{d}{d x} [4 x] + \frac{d}{d x} [- 1]$ .

$\frac{(4 x - 1) (2 x + 5) - (x + 4) (x + 1) (\frac{d}{d x} [4 x] + \frac{d}{d x} [- 1])}{{(4 x - 1)}^{2}}$

Step 3.10

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

$\frac{(4 x - 1) (2 x + 5) - (x + 4) (x + 1) (4 \frac{d}{d x} [x] + \frac{d}{d x} [- 1])}{{(4 x - 1)}^{2}}$

Step 3.11

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

$\frac{(4 x - 1) (2 x + 5) - (x + 4) (x + 1) (4 \cdot 1 + \frac{d}{d x} [- 1])}{{(4 x - 1)}^{2}}$

Step 3.12

Multiply $4$ by $1$ .

$\frac{(4 x - 1) (2 x + 5) - (x + 4) (x + 1) (4 + \frac{d}{d x} [- 1])}{{(4 x - 1)}^{2}}$

Step 3.13

Since $- 1$ is constant with respect to $x$ , the derivative of $- 1$ with respect to $x$ is $0$ .

$\frac{(4 x - 1) (2 x + 5) - (x + 4) (x + 1) (4 + 0)}{{(4 x - 1)}^{2}}$

Step 3.14

Simplify the expression.

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Step 3.14.1

Add $4$ and $0$ .

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

Step 3.14.2

Multiply $4$ by $- 1$ .

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

Step 4

Simplify.

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Step 4.1

Apply the distributive property.

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

Step 4.2

Simplify the numerator.

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Step 4.2.1

Simplify each term.

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Step 4.2.1.1

Expand $(4 x - 1) (2 x + 5)$ using the FOIL Method.

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Step 4.2.1.1.1

Apply the distributive property.

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

Step 4.2.1.1.2

Apply the distributive property.

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

Step 4.2.1.1.3

Apply the distributive property.

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

Step 4.2.1.2

Simplify and combine like terms.

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Step 4.2.1.2.1

Simplify each term.

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Step 4.2.1.2.1.1

Rewrite using the commutative property of multiplication.

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

Step 4.2.1.2.1.2

Multiply $x$ by $x$ by adding the exponents.

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Step 4.2.1.2.1.2.1

Move $x$ .

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

Step 4.2.1.2.1.2.2

Multiply $x$ by $x$ .

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

Step 4.2.1.2.1.3

Multiply $4$ by $2$ .

$\frac{8 x^{2} + 4 x \cdot 5 - 1 (2 x) - 1 \cdot 5 + (- 4 x - 4 \cdot 4) (x + 1)}{{(4 x - 1)}^{2}}$

Step 4.2.1.2.1.4

Multiply $5$ by $4$ .

$\frac{8 x^{2} + 20 x - 1 (2 x) - 1 \cdot 5 + (- 4 x - 4 \cdot 4) (x + 1)}{{(4 x - 1)}^{2}}$

Step 4.2.1.2.1.5

Multiply $2$ by $- 1$ .

$\frac{8 x^{2} + 20 x - 2 x - 1 \cdot 5 + (- 4 x - 4 \cdot 4) (x + 1)}{{(4 x - 1)}^{2}}$

Step 4.2.1.2.1.6

Multiply $- 1$ by $5$ .

$\frac{8 x^{2} + 20 x - 2 x - 5 + (- 4 x - 4 \cdot 4) (x + 1)}{{(4 x - 1)}^{2}}$

Step 4.2.1.2.2

Subtract $2 x$ from $20 x$ .

$\frac{8 x^{2} + 18 x - 5 + (- 4 x - 4 \cdot 4) (x + 1)}{{(4 x - 1)}^{2}}$

Step 4.2.1.3

Multiply $- 4$ by $4$ .

$\frac{8 x^{2} + 18 x - 5 + (- 4 x - 16) (x + 1)}{{(4 x - 1)}^{2}}$

Step 4.2.1.4

Expand $(- 4 x - 16) (x + 1)$ using the FOIL Method.

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Step 4.2.1.4.1

Apply the distributive property.

$\frac{8 x^{2} + 18 x - 5 - 4 x (x + 1) - 16 (x + 1)}{{(4 x - 1)}^{2}}$

Step 4.2.1.4.2

Apply the distributive property.

$\frac{8 x^{2} + 18 x - 5 - 4 x \cdot x - 4 x \cdot 1 - 16 (x + 1)}{{(4 x - 1)}^{2}}$

Step 4.2.1.4.3

Apply the distributive property.

$\frac{8 x^{2} + 18 x - 5 - 4 x \cdot x - 4 x \cdot 1 - 16 x - 16 \cdot 1}{{(4 x - 1)}^{2}}$

Step 4.2.1.5

Simplify and combine like terms.

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Step 4.2.1.5.1

Simplify each term.

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Step 4.2.1.5.1.1

Multiply $x$ by $x$ by adding the exponents.

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Step 4.2.1.5.1.1.1

Move $x$ .

$\frac{8 x^{2} + 18 x - 5 - 4 (x \cdot x) - 4 x \cdot 1 - 16 x - 16 \cdot 1}{{(4 x - 1)}^{2}}$

Step 4.2.1.5.1.1.2

Multiply $x$ by $x$ .

$\frac{8 x^{2} + 18 x - 5 - 4 x^{2} - 4 x \cdot 1 - 16 x - 16 \cdot 1}{{(4 x - 1)}^{2}}$

Step 4.2.1.5.1.2

Multiply $- 4$ by $1$ .

$\frac{8 x^{2} + 18 x - 5 - 4 x^{2} - 4 x - 16 x - 16 \cdot 1}{{(4 x - 1)}^{2}}$

Step 4.2.1.5.1.3

Multiply $- 16$ by $1$ .

$\frac{8 x^{2} + 18 x - 5 - 4 x^{2} - 4 x - 16 x - 16}{{(4 x - 1)}^{2}}$

Step 4.2.1.5.2

Subtract $16 x$ from $- 4 x$ .

$\frac{8 x^{2} + 18 x - 5 - 4 x^{2} - 20 x - 16}{{(4 x - 1)}^{2}}$

Step 4.2.2

Subtract $4 x^{2}$ from $8 x^{2}$ .

$\frac{4 x^{2} + 18 x - 5 - 20 x - 16}{{(4 x - 1)}^{2}}$

Step 4.2.3

Subtract $20 x$ from $18 x$ .

$\frac{4 x^{2} - 2 x - 5 - 16}{{(4 x - 1)}^{2}}$

Step 4.2.4

Subtract $16$ from $- 5$ .

$\frac{4 x^{2} - 2 x - 21}{{(4 x - 1)}^{2}}$