nilai x yqng memenuhi persamaan tan (3x + 30°) untuk 0°≤ x ≤ 360° adalah..

tan (3x + 30°) = √3
tan (3x + 30°) = tan 60°
α = 60°

k = 0
↓↓
3x + 30° = α + k.180°
3x + 30° = 60° + 0.180°
3x = 60° - 30°
3x = 30°
x = 30° : 3 = 10°

k = 1
↓↓
3x + 30° = α + k.180°
3x + 30° = 60° + 1.180°
3x = 60° + 180° - 30°
3x = 210°
x = 210° : 3 = 70°

k = 2
↓↓
3x + 30° = α + k.180°
3x + 30° = 60° + 2.180°
3x + 30° = 60° + 360°
3x = 60° + 360° - 30°
3x = 390°
x = 390° : 3 = 130°

begitu seterusnya sampai angkanya tidak memenuhi (>360°)