Question

Пожалуйста, помогите! Срочно!

cosx+sinx=$frac{1}{2}$

Answer 1

cosx+cos(π/2-x)=1/2
2cosπ/4*cos(x-π/4)=1/2
2*√2/2*cos(x-π/4)=1/2
cos(x-π/4)=√2/4
x-π/4=+-accos√2/4+2πn
x=π/4+-accos√2/4+2πn