How do you simplify cos 85° cos 50° - sin 85° sin 50°?
1 Answer
Nov 29, 2015
Simplify trig expression.
Ans: cos (135)
Explanation:
Apply the trig identity: cos (a + b) = cos a.cos b - sin a.sin b
cos (85 + 50) = cos (135) = cos 85.cos 50 - sin 85.sin 50
