Question

trigonometric problem solve it
√2+ √2+2cos2(θ)

Answer 1

use cos2θ=2cos2θ−1. Therefore our equation is. cos2θ+2cos2θ−2= ... First, cosθ=√32 , ⇒ , θ=30º;330º. Second, cosθ=−√32 , ⇒ , θ=150º ...