Question

cosx+sinx=корень квадратный из двух.

Answer 1

Cosx+sinx=√2
(1/√2)Cosx+(1/√2)sinx=√2·(1/√2)

Cos(π/4)Cosx+sin(π/4)sinx=1
Cos(x-π/4)=1
(x-π/4)=2πn, n∈Z.

x=π/4+2πn, n∈Z.