Give short answers to these questions. — Дайте краткие ответы на эти вопросы. 1 Was Fyodor Shalyapin British?

Cos(3π/2+x/2)-cos(π-x)=1
sinx/2+cosx=1
sinx/2+1-2sin²x/2-1=0
sinx/2-2sin²x/2=0
sinx/2(1-2sinx/2)=0
sinx/2=0⇒x/2=πn⇒x=2πn
sinx/2=1/2⇒x/2=(-1)^n*π/6+πn⇒x=(-1)^n*π/3+2πn