Posted by Anonymus on Tuesday, March 1, 2011 at 5:23pm.
Use Trig identities to verify that sec^4(x)tan^4(x)=1+2tan^2(x), Only work with one side of the equation

Trig  agrin04, Wednesday, March 2, 2011 at 6:25am
sec^4(x)  tan^4(x) =
= (1 + tan^2(x))^2  tan^4(x)
= 1 + 2tan^2(x) + tan^4(x)  tan^4(x)
= 1 + 2tan^2(x)
QED