Calculus Examples

$- \cos (\sqrt{x})$

Step 1

Differentiate using the Constant Multiple Rule.

Tap for more steps...

Step 1.1

Use $\sqrt[n]{a^{x}} = a^{\frac{x}{n}}$ to rewrite $\sqrt{x}$ as $x^{\frac{1}{2}}$ .

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

Step 1.2

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

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

Step 2

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

Tap for more steps...

Step 2.1

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

$- (\frac{d}{d u} [\cos (u)] \frac{d}{d x} [x^{\frac{1}{2}}])$

Step 2.2

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

$- (- \sin (u) \frac{d}{d x} [x^{\frac{1}{2}}])$

Step 2.3

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

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

Step 3

Differentiate using the Power Rule.

Tap for more steps...

Step 3.1

Multiply $- 1$ by $- 1$ .

$1 (\sin (x^{\frac{1}{2}}) \frac{d}{d x} [x^{\frac{1}{2}}])$

Step 3.2

Multiply $\sin (x^{\frac{1}{2}})$ by $1$ .

$\sin (x^{\frac{1}{2}}) \frac{d}{d x} [x^{\frac{1}{2}}]$

Step 3.3

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

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

Step 4

To write $- 1$ as a fraction with a common denominator, multiply by $\frac{2}{2}$ .

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

Step 5

Combine $- 1$ and $\frac{2}{2}$ .

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

Step 6

Combine the numerators over the common denominator.

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

Step 7

Simplify the numerator.

Tap for more steps...

Step 7.1

Multiply $- 1$ by $2$ .

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

Step 7.2

Subtract $2$ from $1$ .

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

Step 8

Move the negative in front of the fraction.

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

Step 9

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

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

Step 10

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

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

Step 11

Move $x^{- \frac{1}{2}}$ to the denominator using the negative exponent rule $b^{- n} = \frac{1}{b^{n}}$ .

$\frac{\sin (x^{\frac{1}{2}})}{2 x^{\frac{1}{2}}}$