Question

Помогите решить

sin^2 x - 4 sin x cos x + 4 cos^2 x = 0

Answer 1

$sin^2x-4sinxcosx+4cos^2x=0 \ (sinx-2cosx)^2=0 \ sinx-2cosx=0 \ sinx=2cosx \ \ frac{sinx}{cosx}= frac{2cosx}{cosx} \ tgx=2 \ x=arctg2+2 pi k$