Question

Sin^2x + sin^2x + cos²x

Answer 1

Answer:

A. 2 sinx cosx - 1 + 2 sin^2 x.

Step-by-step explanation:

sin2x = 2 sinx cosx

cos2x = cos^2x - sin^2x

So sin2x - cos2x = 2 sinx cosx - ( cos^2x - sin^2x)

But cos^2 x = 1 - sin^2 x, so we have:

2 sinx cosx - (1 - sin^2 x - sin^2x)

= 2 sinx cosx - 1 + 2 sin^2 x.