Calculus Examples

$y = \arccos (\frac{2 x}{1 + x^{2}})$

Step 1

Differentiate using the chain rule, which states that $\frac{d}{d x} [f (g (x))]$ is $f' (g (x)) g' (x)$ where $f (x) = \arccos (x)$ and $g (x) = \frac{2 x}{1 + x^{2}}$ .

Tap for more steps...

Step 1.1

To apply the Chain Rule, set $u$ as $\frac{2 x}{1 + x^{2}}$ .

$\frac{d}{d u} [\arccos (u)] \frac{d}{d x} [\frac{2 x}{1 + x^{2}}]$

Step 1.2

The derivative of $\arccos (u)$ with respect to $u$ is $- \frac{1}{\sqrt{1 - u^{2}}}$ .

$- \frac{1}{\sqrt{1 - u^{2}}} \frac{d}{d x} [\frac{2 x}{1 + x^{2}}]$

Step 1.3

Replace all occurrences of $u$ with $\frac{2 x}{1 + x^{2}}$ .

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

Step 2

Differentiate using the Constant Multiple Rule.

Tap for more steps...

Step 2.1

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

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

Step 2.2

Combine fractions.

Tap for more steps...

Step 2.2.1

Multiply $2$ by $- 1$ .

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

Step 2.2.2

Combine $- 2$ and $\frac{1}{\sqrt{1 - {(\frac{2 x}{1 + x^{2}})}^{2}}}$ .

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

Step 2.2.3

Move the negative in front of the fraction.

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

Step 3

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

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

Step 4

Differentiate.

Tap for more steps...

Step 4.1

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

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

Step 4.2

Multiply $1 + x^{2}$ by $1$ .

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

Step 4.3

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

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

Step 4.4

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

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

Step 4.5

Add $0$ and $\frac{d}{d x} [x^{2}]$ .

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

Step 4.6

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

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

Step 4.7

Multiply $2$ by $- 1$ .

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

Step 5

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

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

Step 6

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

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

Step 7

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

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

Step 8

Add $1$ and $1$ .

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

Step 9

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

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

Step 10

Multiply $\frac{1 - x^{2}}{{(1 + x^{2})}^{2}}$ by $\frac{2}{\sqrt{1 - {(\frac{2 x}{1 + x^{2}})}^{2}}}$ .

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

Step 11

Move $2$ to the left of $1 - x^{2}$ .

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

Step 12

Simplify.

Tap for more steps...

Step 12.1

Apply the product rule to $\frac{2 x}{1 + x^{2}}$ .

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

Step 12.2

Apply the product rule to $2 x$ .

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

Step 12.3

Apply the distributive property.

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

Step 12.4

Simplify each term.

Tap for more steps...

Step 12.4.1

Multiply $2$ by $1$ .

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

Step 12.4.2

Multiply $- 1$ by $2$ .

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

Step 12.5

Raise $2$ to the power of $2$ .

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

Step 12.6

Simplify the numerator.

Tap for more steps...

Step 12.6.1

Factor $2$ out of $2 - 2 x^{2}$ .

Tap for more steps...

Step 12.6.1.1

Factor $2$ out of $2$ .

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

Step 12.6.1.2

Factor $2$ out of $- 2 x^{2}$ .

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

Step 12.6.1.3

Factor $2$ out of $2 (1) + 2 (- x^{2})$ .

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

Step 12.6.2

Rewrite $1$ as $1^{2}$ .

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

Step 12.6.3

Since both terms are perfect squares, factor using the difference of squares formula, $a^{2} - b^{2} = (a + b) (a - b)$ where $a = 1$ and $b = x$ .

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

Step 12.7

Simplify the denominator.

Tap for more steps...

Step 12.7.1

Write $1$ as a fraction with a common denominator.

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

Step 12.7.2

Combine the numerators over the common denominator.

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

Step 12.7.3

Rewrite $\frac{{(1 + x^{2})}^{2} - 4 x^{2}}{{(1 + x^{2})}^{2}}$ in a factored form.

Tap for more steps...

Step 12.7.3.1

Rewrite $4 x^{2}$ as ${(2 x)}^{2}$ .

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

Step 12.7.3.2

Since both terms are perfect squares, factor using the difference of squares formula, $a^{2} - b^{2} = (a + b) (a - b)$ where $a = 1 + x^{2}$ and $b = 2 x$ .

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

Step 12.7.3.3

Simplify.

Tap for more steps...

Step 12.7.3.3.1

Factor using the perfect square rule.

Tap for more steps...

Step 12.7.3.3.1.1

Rearrange terms.

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

Step 12.7.3.3.1.2

Rewrite $1$ as $1^{2}$ .

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

Step 12.7.3.3.1.3

Check that the middle term is two times the product of the numbers being squared in the first term and third term.

$2 x = 2 \cdot 1 \cdot x$

Step 12.7.3.3.1.4

Rewrite the polynomial.

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

Step 12.7.3.3.1.5

Factor using the perfect square trinomial rule $a^{2} + 2 a b + b^{2} = {(a + b)}^{2}$ , where $a = 1$ and $b = x$ .

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

Step 12.7.3.3.2

Factor using the perfect square rule.

Tap for more steps...

Step 12.7.3.3.2.1

Rearrange terms.

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

Step 12.7.3.3.2.2

Rewrite $1$ as $1^{2}$ .

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

Step 12.7.3.3.2.3

Check that the middle term is two times the product of the numbers being squared in the first term and third term.

$1 \cdot 2 x = 2 \cdot 1 \cdot x$

Step 12.7.3.3.2.4

Rewrite the polynomial.

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

Step 12.7.3.3.2.5

Factor using the perfect square trinomial rule $a^{2} - 2 a b + b^{2} = {(a - b)}^{2}$ , where $a = 1$ and $b = x$ .

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

Step 12.7.4

Rewrite ${(1 + x)}^{2} {(1 - x)}^{2}$ as ${((1 + x) (1 - x))}^{2}$ .

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

Step 12.7.5

Rewrite $\frac{{((1 + x) (1 - x))}^{2}}{{(1 + x^{2})}^{2}}$ as ${(\frac{(1 + x) (1 - x)}{1 + x^{2}})}^{2}$ .

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

Step 12.7.6

Pull terms out from under the radical, assuming positive real numbers.

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

Step 12.8

Combine ${(1 + x^{2})}^{2}$ and $\frac{(1 + x) (1 - x)}{1 + x^{2}}$ .

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

Step 12.9

Reduce the expression by cancelling the common factors.

Tap for more steps...

Step 12.9.1

Reduce the expression $\frac{{(1 + x^{2})}^{2} (1 + x) (1 - x)}{1 + x^{2}}$ by cancelling the common factors.

Tap for more steps...

Step 12.9.1.1

Factor $1 + x^{2}$ out of ${(1 + x^{2})}^{2} (1 + x) (1 - x)$ .

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

Step 12.9.1.2

Multiply by $1$ .

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

Step 12.9.1.3

Cancel the common factor.

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

Step 12.9.1.4

Rewrite the expression.

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

Step 12.9.2

Divide $((1 + x^{2}) (1 + x)) (1 - x)$ by $1$ .

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

Step 12.10

Cancel the common factor of $1 + x$ .

Tap for more steps...

Step 12.10.1

Cancel the common factor.

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

Step 12.10.2

Rewrite the expression.

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

Step 12.11

Cancel the common factor of $1 - x$ .

Tap for more steps...

Step 12.11.1

Cancel the common factor.

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

Step 12.11.2

Rewrite the expression.

$- \frac{2}{1 + x^{2}}$