Write cos(37°)+cos(95°)as a product, with positive angles

Answer 1

Use the following sum-to-product identity:

cos(x) + cos(y) = 2 cos((x+y)/2) cos((x-y)/2)

In order to get positive angles, you'll want x > y. Note that:

cos(37) + cos(95) = cos(95) + cos(37)

and thus use x = 95, y = 37.