Question

Prove that sin^2 pi/6 + cos^2 pi/3 - tan^2 pi/4 = -1/2

Answer 1

See below.

Explanation:

sin pi/6 = 1/2

cos pi/3 = 1/2

tan pi/4 = 1

So sin^2 pi/6 + cos^2 pi/3 - tan^2 pi/4

= 1/4 + 1/4 - 1

= -1/2.