Part 1)

Question

Evaluate tan 7.5

Part 2)

Evaluate exactly cos (-(45pi(4)))

Answer 1

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.