(cos x-√2/2)(sin x+√2/2)=0

(cosx - √2/2)=0, x=+-π/4 + 2πk, k∈Z (sinx + √2/2)=0, x= -π/4 +2πk, x=-3π/4 +2πk, k∈Z объединяем ответы, получаем x=π/4 + πk, x= -π/4 +2πk, k∈Z