Question

Решите Уравнение: $cos frac{x}{2} +sin frac{x}{2} =-1$

Answer 1

(sinx/2+cosx/2)^2=(-1)^2
Sin^2x/2+cos^2x/2+2sinx/2cosx/2=1
1+sinx=1
Sinx=0
x=+-пk