hasil tan 3x = tan Π/2

3x = π/2
3x = 90°
x = 30°

tan 3x = Tan π/2
3x = π/2 + k . π
x = π/6 + k . π/3
x = π/6 + k . 2π/6
x = π/6 => untuk k = 0
x = 3π/6 => untuk k = 1
x = 5π/6 => untuk k = 2
x = 7π/6 => untuk k = 3
x = 9π/6 => untuk k = 4
x = 11π/6 => untuk k = 5
x = 13π/2 (tidak memenuhi) => untuk k = 6
HP = {π/6, 3π/6, 5π/6, 7π/6, 9π/6, 11π/6}
= {π/6, π/2, 5π/6, 7π/6, 3π/2, 11π/6}