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.