Question

which of the following are identities? check all that apply A. cot^2x+1=csc^2x B.tan^2=1-sec^2x C.sin2^x=1=cos^2x D.sin^2x+cos^2x=1

Answer 1

Sin^2x+cos^x=1 from there you can derive the other two identities by dividing by cos and sin
The answer is A and D