# How do you integrate int x^3/sqrt(x^2+25) dx using trigonometric substitution?

Jan 13, 2016

I'll start you off.....
Consider the following right triangle:

#### Explanation:

Find the following:
1)tan(theta)
2)sec(theta)
3)dx/(d theta)
4)x^3
5)sqrt(x^2+25)

You will then systematically replace all x terms (rectangular) with
$\theta$ terms (trigonometric).

It's your turn now to get your hands dirty and fill in all algebraic details.