Question

cos^2 x - cos x sin x =0

Answer 1

$cos^2x-cosxsinx=0\cosx(cosx-sinx)=0\\cosx=0\x=frac{pi}{2}+pi n,;nin Z;\\cosx-sinx=0|:sinx,;sinx neq 0,;xneq pi n, ;nin Z;\ctgx-1=0\ctgx=1\x=arcctg1+pi n\x=frac{pi}{4}+pi n,;nin Z.$