2cos^2x+√3cosx=0 4cos^2x-3=0

2cos²(x) + √3*cos(x) = 0 --> cos(x) = 0; cos(x) = -√3/2 --> x = π/2 + πk; x = ±5π/6 + 2πk. 4cos²(x) - 3 = 0 --> cos(x) = ±√3/2 --> x = π/6 + πk; x = 5π/6 + πk. 3tan²(x) - 3tan(x) = 0 --> tan(x) = 0; tan(x) = 1 --> x = πk; x = π/4 + πk. 4sin²(x) - 1 = 0 --> sin(x) = ±1/2 --> x = ±π/6 + πk.