# Math Help - Integrating this function

1. ## Integrating this function

Hi all,

How do I integrate

$\int \frac{dx}{(x^2 + y^2)^{3/2}}$

thanks

2. Originally Posted by kuntah
Hi all,

How do I integrate

$\int \frac{dx}{(x^2 + y^2)^{3/2}}$

thanks
In this y will be considered a constant, so first let
$x = y \cdot u implies dx = y~du$
or

So
$\int \frac{dx}{(x^2 + y^2)^{3/2}} = \int \frac{y~du}{(y^2u^2 + y^2)^{3/2}}$

$= \frac{1}{y^2} \int \frac{du}{(u^2 + 1)^{3/2}}$

Can you do this now?

-Dan

3. He thanks Dan