Originally Posted by

**Jhevon** i don't see your problem? just plug in the required values into the reduction formula (this is by the way too much work, i'd use a simple substitution to do this).

recall: $\displaystyle \int \sin^n u \cos^m u ~du = - \frac {\sin^{n - 1} u \cos^{m + 1} u}{n + m} + \frac {n - 1}{n + m} \int \sin^{n - 2} u \cos^m u~du$

or alternately:

$\displaystyle \int \sin^n u \cos^m u ~du = \frac {\sin^{n + 1} u \cos^{m - 1} u}{n + m} + \frac {m - 1}{n + m} \int \sin^n u \cos^{m - 2} u~du$

as i said, this is way more trouble than it's worth. if you are not required to use reduction, do the integral with substitution