Trig identities on the Math Sat 2

Hi everyone, I will soon be taking the Sat Math 2 subject test and am stressing over the trig identities (sum and difference/half/double). I just think it’s too much to memorize. Does anyone have any experience with these on the Math 2 test? If so, how often do they appear? Any tips?

If anything, learn the formulas for sin(x+y), cos(x+y), and tan(x+y). The rest of the formulas (double angle, half angle) can be derived from those.

Right. And if you know the sum formulas, it’s easy enough to also derive the difference.