Calculus Examples

$\int \frac{\ln ({(x)}^{7})}{x} d x$

Step 1

Rewrite $\frac{\ln (x^{7})}{x}$ as $\frac{7 \ln (x)}{x}$ .

$\int \frac{7 \ln (x)}{x} d x$

Step 2

Since $7$ is constant with respect to $x$ , move $7$ out of the integral.

$7 \int \frac{\ln (x)}{x} d x$

Step 3

Let $u = \ln (x)$ . Then $d u = \frac{1}{x} d x$ , so $x d u = d x$ . Rewrite using $u$ and $d$ $u$ .

Tap for more steps...

Step 3.1

Let $u = \ln (x)$ . Find $\frac{d u}{d x}$ .

Tap for more steps...

Step 3.1.1

Differentiate $\ln (x)$ .

$\frac{d}{d x} [\ln (x)]$

Step 3.1.2

The derivative of $\ln (x)$ with respect to $x$ is $\frac{1}{x}$ .

$\frac{1}{x}$

Step 3.2

Rewrite the problem using $u$ and $d u$ .

$7 \int u d u$

Step 4

By the Power Rule, the integral of $u$ with respect to $u$ is $\frac{1}{2} u^{2}$ .

$7 (\frac{1}{2} u^{2} + C)$

Step 5

Simplify.

Tap for more steps...

Step 5.1

Rewrite $7 (\frac{1}{2} u^{2} + C)$ as $7 (\frac{1}{2}) u^{2} + C$ .

$7 (\frac{1}{2}) u^{2} + C$

Step 5.2

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

$\frac{7}{2} u^{2} + C$

Step 6

Replace all occurrences of $u$ with $\ln (x)$ .

$\frac{7}{2} \ln^{2} (x) + C$