Posted by **Melody** on Sunday, January 3, 2010 at 4:07pm.

Are any of these three problems identities?

1. Cos^2x-sin^2x=1-2sin^2x

2. Sinxsecx=cosxcscx

3. Sec^4x-tan^4/sec^2x=1+sin^2x

If so, how can you conclude that any of them are identities?

## Answer This Question

## Related Questions

- Trig - Are any of these three problems identities? 1. Cos^2x-sin^2x=1-2sin^2x 2...
- Trig Identities - Proving identities: 1) 1+ 1/tan^2x = 1/sin^2x 2) 2sin^2 x-1 = ...
- trig 26 - simplify to a constant or trig func. 1. sec ²u-tan ²u/cos ²v+sin ²v ...
- Trig Identities - Please help...I'm not understanding trig identities and how to...
- Trig Identities - Prove the following identities: 13. tan(x) + sec(x) = (cos(x...
- Trigonometry - Verify/Solve the identities. 1.) SIN^1/2 X COS X-SIN^5/2 X COS X ...
- Mathematics - Trigonometric Identities - Let y represent theta Prove: 1 + 1/tan^...
- trig - how do you start this equation i've been tryng it for 20min. sec^6x(...
- Integration - Intergrate ¡ì sec^3(x) dx could anybody please check this answer. ...
- Precalculus - Verify the identities. Cos^2x - sin^2x = 2cos^2x - 1 When ...

More Related Questions