But it boils down to solving an integral.

Now I have the solution from the text book but I can not figure out how they solved it. Can anyone on here do this integration. as follows

integral x/(x^2+y^2)^(3/2) dy = y/(x sqrt(x^2+y^2))+constant

How was that worked out? Really would appreciate any ones help on this.

It looks really simple but I have tried substitution and looked up all the ordinary qouted lists of integrals but I can't do it.