Question

(cosx - sinx)^2 + (cosx + sinx)^2 = 2

Iam in this step:

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

How can I make the equation on the right equal 2

Answer 1

oh, please. What is the first and most fundamental trig identity you ever learned?

cos^2 + sin^2 = 1

right? Time for the duhh! and head slap.

Answer 2

Thank You