Simplify the expression by using a double angle formula

cos^2 4theta-sin^2 4theta

Question

Mathematics

Alanna Cook

29 April, 20:00

Simplify the expression by using a double angle formula

cos^2 4theta-sin^2 4theta

+1

Answers (1)

Know the Answer?

Xavier Cross · Answer 1

Double angle formula for cos (2x) is

cos (2x) = cos^2 (x) - sin^2 (x)

Substitute x=4theta, then

cos (8theta) = cos^2 (4theta) - sin^2 (4theta)

=>

cos^2 (4theta) - sin^2 (4theta) = cos (8theta)

Simplify the expression by using a double angle formulacos^2 4theta-sin^2 4theta

Simplify the expression by using a double angle formula

cos^2 4theta-sin^2 4theta