# Integral of cotx squared

1. Sep 30, 2009

### Eshi

1. The problem statement, all variables and given/known data
find the integral of (cscx)2 between pie/6 to pie/2

3. The attempt at a solution

cot2x = 1 / sin2x * cos2x / cos2x
which becomes..
tan2x * sec2x
then i substituted u for tan x, and turned the integral into..
u2du = u3 / 3
which is..
tan3x / 3 between pie/6 and pie/2.

However, tan is undefined at pie/6!! what do i do?

2. Sep 30, 2009

### Bohrok

No, that last line should be cot2x * sec2x, and the cot in the first line should be csc.

That's not true; it is defined at $\pi$/6. What is sin$\pi$/6 and cos$\pi$/6? Put sine over cosine.