# Math Help - Hard integral

1. ## Hard integral

I didn't success to solve the intgral of this function
x(cos(x))/((sin(x))^3) dx

2. Start by integrating by parts:

$u = x$

$du = dx$

$dv = \frac{\cos x}{\sin^3 x} dx$

$v = -\frac{1}{2 \sin^2 x}$

$\int \frac{x \cos x}{\sin^3 x} dx = -\frac{x}{2 \sin^2 x} + \int \frac{1}{2 \sin^2 x} dx$

3. wow, thanks
I didn't think about it.