How do you simplify #cos(-x) cos x-sin(-x) sin x#?
1 Answer
Aug 5, 2015
Simplify: cos (-x)cos x - sin (-x)sin x
Ans: 1
Explanation:
Reminder: cos (-x) = cos x and sin (-x) = -sin x
The trig expression results in:
cos^2 x + sin^2 x = 1
