Integration question

1. Jul 9, 2008

Andrew123

hi guys just a quick proof i need help with please:

if a = pi / (2-b)

prove the integral from 0 to pi/2 of d(b) / [1 + tan(b)] equals the integral from 0 to pi/2 of

d(a) / [1 + cot(a)]

cheers guys!

2. Jul 9, 2008

CompuChip

I don't quite see how to get that answer yet, but I'd start doing the change of variables properly.