Question

What is the value of cos [(180 – θ)/2] cos [(180 – 9θ)/2] + sin [(180 – 3θ)/2] sin [(180 – 13θ)/2]?

A) sin 2θ sin 4θ B) cos 2θ cos 6θ C) sin 2θ sin 6θ D) cos 2θ cos 4θ

Answer 1

Answer:

Step-by-step Explanation