help?
Q:
Evaluate
$\displaystyle \int \frac{\sqrt{9-x^2}}{x^2} dx$
Try the change of variable:
$\displaystyle x=3\cos(u)$.
Which transforms the integral to:
$\displaystyle -\int \tan ^2(u) du =u-\tan(u)$,
if I have done this right, and from here bob's your uncle
RonL