posted by Sophie .
Evaluate tan 7.5
Evaluate exactly cos (-(45pi(4)))
1. I recommend usng a calculator (in radians mode) or search Google with
< tan 7.5 = > in the search window.
2. Remember that you can subtract multiples of 2 pi from the argument of any trig function and get the same answer.
-45 pi*4 = -180 pi; the cosine of that is the same as the cosine of zero.