1)2cos 2x = 1 2) 2 sin x/2 - 1 = 0

1. 2cosx=1 cos2x=1/2 2x=+-arccos(1/2)+2πn, n∈Z 2x=+-π/3+2πn, n∈x | :2 x=+-π/6+πn, n∈Z 2. 2sin(x/2)-1=0 2sin(x/2)=1 sin(x/2)=1/2 [latex] \frac{x}{2} =(-1) ^{n}*arcsin \frac{1}{2}+ \pi n, [/latex]  n∈Z [latex] \frac{x}{2} = (-1)^{n} * \frac{ \pi }{6} + \pi n, [/latex]n∈Z  |*2 [latex]x= (-1)^{n} * \frac{ \pi }{3}+2 \pi n, [/latex]n∈Z