Posted by Melody on Sunday, January 3, 2010 at 4:07pm.
Are any of these three problems identities?
1. Cos^2xsin^2x=12sin^2x
2. Sinxsecx=cosxcscx
3. Sec^4xtan^4/sec^2x=1+sin^2x
If so, how can you conclude that any of them are identities?

Trig  drwls, Sunday, January 3, 2010 at 7:21pm
Identities are trigonometric equations that must be valid for any value of the angle. That is only true for the first equation.