# Homework Help: Finding an integral

1. Sep 19, 2005

### Stevecgz

I'm attempting to find:
$$\int \cos^2x\tan^3x dx$$
I've tried substitution and integration by parts but I'm having no success. Can someone help me out on how I get this one started?

Steve

Last edited: Sep 19, 2005
2. Sep 19, 2005

### dextercioby

It's no big deal.

$$\int \frac{\sin^{3}x}{\cos x} \ dx =\int \frac{\sin x \left(1-\cos^{2}x\right)}{\cos x} \ dx =\int \tan x \ dx -\int \sin x \ d\left(\sin x\right) = ...$$

Daniel.

3. Sep 19, 2005

### Stevecgz

Thanks dextercioby, I understand it now.

Steve