# identity question

• Aug 14th 2009, 10:13 PM
smmmc
identity question
Hey need help on these

q(c) can we just let theta=pi
• Aug 14th 2009, 10:38 PM
CaptainBlack
Quote:

Originally Posted by smmmc
Hey need help on these

q(c) can we just let theta=pi

No, this is an identity that you are supposed to show is true for any $\theta$ and $\phi$.

One way to do this is to replace all the $\cot$'s on the right by $1/\tan$'s and simplifying.

CB