Trigonometrymedium · Past Paper

Simplify cos^4 A - sin^4 A.

A1
Bcos(2A)
Csin(2A)
D0

✓ Correct Answer: Bcos(2A)

(cos^2 A - sin^2 A)(cos^2 A + sin^2 A) = cos(2A) * 1 = cos(2A).

Share this question

More from Trigonometry