Calculus Examples

$f (x) = \frac{3 x^{2} - 5 x}{x^{2} + 1}$

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 $f (x) = 3 x^{2} - 5 x$ and $g (x) = x^{2} + 1$ .

$\frac{(x^{2} + 1) \frac{d}{d x} [3 x^{2} - 5 x] - (3 x^{2} - 5 x) \frac{d}{d x} [x^{2} + 1]}{{(x^{2} + 1)}^{2}}$

Step 2

By the Sum Rule, the derivative of $3 x^{2} - 5 x$ with respect to $x$ is $\frac{d}{d x} [3 x^{2}] + \frac{d}{d x} [- 5 x]$ .

$\frac{(x^{2} + 1) (\frac{d}{d x} [3 x^{2}] + \frac{d}{d x} [- 5 x]) - (3 x^{2} - 5 x) \frac{d}{d x} [x^{2} + 1]}{{(x^{2} + 1)}^{2}}$

Step 3

Evaluate $\frac{d}{d x} [3 x^{2}]$ .

Tap for more steps...

Step 3.1

Since $3$ is constant with respect to $x$ , the derivative of $3 x^{2}$ with respect to $x$ is $3 \frac{d}{d x} [x^{2}]$ .

$\frac{(x^{2} + 1) (3 \frac{d}{d x} [x^{2}] + \frac{d}{d x} [- 5 x]) - (3 x^{2} - 5 x) \frac{d}{d x} [x^{2} + 1]}{{(x^{2} + 1)}^{2}}$

Step 3.2

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

$\frac{(x^{2} + 1) (3 (2 x) + \frac{d}{d x} [- 5 x]) - (3 x^{2} - 5 x) \frac{d}{d x} [x^{2} + 1]}{{(x^{2} + 1)}^{2}}$

Step 3.3

Multiply $2$ by $3$ .

$\frac{(x^{2} + 1) (6 x + \frac{d}{d x} [- 5 x]) - (3 x^{2} - 5 x) \frac{d}{d x} [x^{2} + 1]}{{(x^{2} + 1)}^{2}}$

Step 4

Evaluate $\frac{d}{d x} [- 5 x]$ .

Tap for more steps...

Step 4.1

Since $- 5$ is constant with respect to $x$ , the derivative of $- 5 x$ with respect to $x$ is $- 5 \frac{d}{d x} [x]$ .

$\frac{(x^{2} + 1) (6 x - 5 \frac{d}{d x} [x]) - (3 x^{2} - 5 x) \frac{d}{d x} [x^{2} + 1]}{{(x^{2} + 1)}^{2}}$

Step 4.2

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

$\frac{(x^{2} + 1) (6 x - 5 \cdot 1) - (3 x^{2} - 5 x) \frac{d}{d x} [x^{2} + 1]}{{(x^{2} + 1)}^{2}}$

Step 4.3

Multiply $- 5$ by $1$ .

$\frac{(x^{2} + 1) (6 x - 5) - (3 x^{2} - 5 x) \frac{d}{d x} [x^{2} + 1]}{{(x^{2} + 1)}^{2}}$

Step 5

Differentiate.

Tap for more steps...

Step 5.1

By the Sum Rule, the derivative of $x^{2} + 1$ with respect to $x$ is $\frac{d}{d x} [x^{2}] + \frac{d}{d x} [1]$ .

$\frac{(x^{2} + 1) (6 x - 5) - (3 x^{2} - 5 x) (\frac{d}{d x} [x^{2}] + \frac{d}{d x} [1])}{{(x^{2} + 1)}^{2}}$

Step 5.2

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

$\frac{(x^{2} + 1) (6 x - 5) - (3 x^{2} - 5 x) (2 x + \frac{d}{d x} [1])}{{(x^{2} + 1)}^{2}}$

Step 5.3

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

$\frac{(x^{2} + 1) (6 x - 5) - (3 x^{2} - 5 x) (2 x + 0)}{{(x^{2} + 1)}^{2}}$

Step 5.4

Add $2 x$ and $0$ .

$\frac{(x^{2} + 1) (6 x - 5) - (3 x^{2} - 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6

Simplify.

Tap for more steps...

Step 6.1

Apply the distributive property.

$\frac{(x^{2} + 1) (6 x - 5) + (- (3 x^{2}) - (- 5 x)) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.2

Apply the distributive property.

$\frac{(x^{2} + 1) (6 x - 5) - (3 x^{2}) (2 x) - (- 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.3

Simplify the numerator.

Tap for more steps...

Step 6.3.1

Simplify each term.

Tap for more steps...

Step 6.3.1.1

Expand $(x^{2} + 1) (6 x - 5)$ using the FOIL Method.

Tap for more steps...

Step 6.3.1.1.1

Apply the distributive property.

$\frac{x^{2} (6 x - 5) + 1 (6 x - 5) - (3 x^{2}) (2 x) - (- 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.1.2

Apply the distributive property.

$\frac{x^{2} (6 x) + x^{2} \cdot - 5 + 1 (6 x - 5) - (3 x^{2}) (2 x) - (- 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.1.3

Apply the distributive property.

$\frac{x^{2} (6 x) + x^{2} \cdot - 5 + 1 (6 x) + 1 \cdot - 5 - (3 x^{2}) (2 x) - (- 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.2

Simplify each term.

Tap for more steps...

Step 6.3.1.2.1

Rewrite using the commutative property of multiplication.

$\frac{6 x^{2} x + x^{2} \cdot - 5 + 1 (6 x) + 1 \cdot - 5 - (3 x^{2}) (2 x) - (- 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.2.2

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

Tap for more steps...

Step 6.3.1.2.2.1

Move $x$ .

$\frac{6 (x \cdot x^{2}) + x^{2} \cdot - 5 + 1 (6 x) + 1 \cdot - 5 - (3 x^{2}) (2 x) - (- 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.2.2.2

Multiply $x$ by $x^{2}$ .

Tap for more steps...

Step 6.3.1.2.2.2.1

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

$\frac{6 (x^{1} x^{2}) + x^{2} \cdot - 5 + 1 (6 x) + 1 \cdot - 5 - (3 x^{2}) (2 x) - (- 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.2.2.2.2

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

$\frac{6 x^{1 + 2} + x^{2} \cdot - 5 + 1 (6 x) + 1 \cdot - 5 - (3 x^{2}) (2 x) - (- 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.2.2.3

Add $1$ and $2$ .

$\frac{6 x^{3} + x^{2} \cdot - 5 + 1 (6 x) + 1 \cdot - 5 - (3 x^{2}) (2 x) - (- 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.2.3

Move $- 5$ to the left of $x^{2}$ .

$\frac{6 x^{3} - 5 \cdot x^{2} + 1 (6 x) + 1 \cdot - 5 - (3 x^{2}) (2 x) - (- 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.2.4

Multiply $6 x$ by $1$ .

$\frac{6 x^{3} - 5 x^{2} + 6 x + 1 \cdot - 5 - (3 x^{2}) (2 x) - (- 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.2.5

Multiply $- 5$ by $1$ .

$\frac{6 x^{3} - 5 x^{2} + 6 x - 5 - (3 x^{2}) (2 x) - (- 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.3

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

Tap for more steps...

Step 6.3.1.3.1

Move $x$ .

$\frac{6 x^{3} - 5 x^{2} + 6 x - 5 - (3 (x \cdot x^{2})) \cdot 2 - (- 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.3.2

Multiply $x$ by $x^{2}$ .

Tap for more steps...

Step 6.3.1.3.2.1

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

$\frac{6 x^{3} - 5 x^{2} + 6 x - 5 - (3 (x^{1} x^{2})) \cdot 2 - (- 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.3.2.2

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

$\frac{6 x^{3} - 5 x^{2} + 6 x - 5 - (3 x^{1 + 2}) \cdot 2 - (- 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.3.3

Add $1$ and $2$ .

$\frac{6 x^{3} - 5 x^{2} + 6 x - 5 - (3 x^{3}) \cdot 2 - (- 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.4

Multiply $3$ by $- 1$ .

$\frac{6 x^{3} - 5 x^{2} + 6 x - 5 - 3 x^{3} \cdot 2 - (- 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.5

Multiply $2$ by $- 3$ .

$\frac{6 x^{3} - 5 x^{2} + 6 x - 5 - 6 x^{3} - (- 5 x) (2 x)}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.6

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

Tap for more steps...

Step 6.3.1.6.1

Move $x$ .

$\frac{6 x^{3} - 5 x^{2} + 6 x - 5 - 6 x^{3} - (- 5 (x \cdot x)) \cdot 2}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.6.2

Multiply $x$ by $x$ .

$\frac{6 x^{3} - 5 x^{2} + 6 x - 5 - 6 x^{3} - (- 5 x^{2}) \cdot 2}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.7

Multiply $- 5$ by $- 1$ .

$\frac{6 x^{3} - 5 x^{2} + 6 x - 5 - 6 x^{3} + 5 x^{2} \cdot 2}{{(x^{2} + 1)}^{2}}$

Step 6.3.1.8

Multiply $2$ by $5$ .

$\frac{6 x^{3} - 5 x^{2} + 6 x - 5 - 6 x^{3} + 10 x^{2}}{{(x^{2} + 1)}^{2}}$

Step 6.3.2

Combine the opposite terms in $6 x^{3} - 5 x^{2} + 6 x - 5 - 6 x^{3} + 10 x^{2}$ .

Tap for more steps...

Step 6.3.2.1

Subtract $6 x^{3}$ from $6 x^{3}$ .

$\frac{- 5 x^{2} + 6 x - 5 + 0 + 10 x^{2}}{{(x^{2} + 1)}^{2}}$

Step 6.3.2.2

Add $- 5 x^{2} + 6 x - 5$ and $0$ .

$\frac{- 5 x^{2} + 6 x - 5 + 10 x^{2}}{{(x^{2} + 1)}^{2}}$

Step 6.3.3

Add $- 5 x^{2}$ and $10 x^{2}$ .

$\frac{5 x^{2} + 6 x - 5}{{(x^{2} + 1)}^{2}}$