2sin-√3=0

Cos2x=√2/2

Sin+1/√2=0

1) 2sinx-√3=0, 2sinx=√3, sinx = (√3) / 2

sin (π/3) = (√3) / 2, sin (2π/3) = (√3/2)

x1=π/3 + 2kπ, k∈Z

x2=2π/3 + 2kπ, k∈Z

2) cos2x = (√2) / 2

cos (π/4) = (√2) / 2, cos (7π/4) = (√2) / 2

2x=π/4+2kπ, x1=π/8+kπ, k∈Z

2x=7π/4+2kπ, x2=7π/8 + kπ, k∈Z

3) sinx+1/√2=0, sinx=-1/√2, sinx=-√2/2

sin (5π/4) = - √2/2, sin (7π/4) = - √2/2

x1=5π/4+2kπ, k∈Z

x2=7π/4+2kπ, k∈Z