Question

HURRY!!!! Which of the following are identities? Check all that apply.
a. sin2x = 1 + cos2x
b. sin2x + cos2x = 1
c. tan2x = 1 - sec2x
d. cot2x + 1 = csc2x

Answer 1

I think B works, but what else?

Answer 2

\[\sin^2x+\cos^2 x=1\]
\[\cot^2x+1=cosec^2 x\]