# Quick integration question

1. Sep 1, 2004

### Ethereal

How does one integrate the following:
By using a suitable substitution, evaluate:
$$\int \frac{\sqrt{x+1}}{x+3} dx$$

I tried $$x=tan^2 \theta, x+1=y$$, but the whole thing got messier. Anyone knows the correct substitution to make?

2. Sep 1, 2004

### Tide

Here's a start: Do it in stages using the first transformation to get rid of the +1 under the radical so the integrand becomes $\frac {\sqrt{x}}{x+2}$ then let $y = \sqrt {x}$. It should be apparent what to do next.

3. Sep 2, 2004

### Ethereal

Thanks for your help. I managed to solve it, required 2 substitutions as you said!

4. Sep 2, 2004

Way to go!