2cos3x = √3 cos3x = √3 / 2 3x = arccos(√3 / 2) + 2πk, k є Z 3x = ±π/6 + 2πk, k є Z x = ±π/18 + 2πk, k є Z
2cos3x = √3
cos3x = √3 / 2
3x = arccos(√3 / 2) + 2πk, k є Z
3x = ±π/6 + 2πk, k є Z
x = ±π/18 + 2πk, k є Z