Question

Помогите!$a)4-2cos2x-4 \sqrt{2} sinx=0 \\ b)5+2cos2x-4 \sqrt{3}cosx=0$

Answer 1

a)4-2(1-2sinx)-4√2sinx=0
4-2+4sin²x-4√2sinx=0
4sin²x-4√2sinx+2=0
(2sinx-√2)²=0
2sinx-√2=0
sinx=√2/2
x=(-1)^n*π/4+πn
b)5+2(2cos²x-1)-4√3cosx=0
5+4cos²x-2-4√3cosx=0
4cos²x-4√3cosx+3=0
(2cosx-√3)²=0
2cosx-√3=0
cosx=√3/2
x=+-π/6+2πn