(1+ cos^2 theta)(1- cot^2 theta)= 1

I have no idea how (1+ cos^2 theta)(1- cot^2 theta) could possibly equal to 1. Any ideas?

Printable View

- October 9th 2012, 04:03 PMavatartiger2establish this identity
(1+ cos^2 theta)(1- cot^2 theta)= 1

I have no idea how (1+ cos^2 theta)(1- cot^2 theta) could possibly equal to 1. Any ideas? - October 9th 2012, 04:14 PMskeeterRe: establish this identity
- October 9th 2012, 04:24 PMjohnsomeoneRe: establish this identity
Idea: First, unpack cotangent in terms of sine and cosine. Then simplify (multiply out - or something even better if you see it) the left hand side.

Also, I believe that skeeter's correct about the actual problem intended. - October 9th 2012, 04:50 PMavatartiger2Re: establish this identity
yeah! i looked over the problem and I think the textbook might have switched the signs! (1-cos^2 theta)(1+ cot^2 theta) does simplify to 1. I kept doing the other problem over and over again. thanks for telling me! what a relief!