How do you integrate 1/sqrt((a^2-x^2)^3)?

let x= a sin theta
dx =a cos theta
a^2-x^2= a^2(1-sin^2 theta)= a^2 cos^2 theta
sqrt(x^2-a^20 = a cos(theta)
Integral will be = a cos theta/a^3 cos ^3 theta dtheta
1/a^ 2 1/cos ^2 theta d theta=1/a^2 sec^2 theta. The integral will be
1/a^2 tan theta= 1/a^2 sin theta/ cos theta
sin theta = x/a.
cos theta = sqrt(1-x^2/a^2)
The answer is
1/a^2 * x/a * a/sqrt(a^2-x^2)= 1/a x/(sqrt(a^2-x^2) + c
This is the integral.