Express cos(5θ) in terms of cos θ via De Moivre.

Express cos(5θ) in terms of cos θ via De Moivre.

A cos(5θ) = 5cos θ − 20cos^3θ + 16cos^5θ

B cos(5θ) = 10cos^3θ − 5cos θ

C cos(5θ) = 16cos^5θ − 20cos^3θ + 5cos θ

D cos(5θ) = 5cos^5θ − 10cos^3θ + cos θ

Solution

Correct Answer: Option C