Hasil persamaan trigonometri tan 2A+tan A=0

tan 2A + tan A = 0
2tan A/(1 - tan² A) + tan A (1 - tan² A)/(1 - tan² A) = 0
2tan A + tan A - tan³ A = 0
tan³ A - 3tan A = 0
tan A (tan² A - 3) = 0
tan A = 0 --> A = 0° , 180°
tan² A = 3
tan A = √3 --> A = 60° , 240°
tan A = -√3 --> A = 120° , 300°

HP = {0°, 60°, 120°, 180°, 240° , 300°}