Question

Hasil dari persamaan trigonometri sin 3 x = cos 3 x , 180* < x < 1080* adalah

Answer 1

Sin 3x = cos 3x
sin 3x = sin (90 - 3x)
3x = 90 - 3x + k.360
3x + 3x = 90 + k.360
6x = 90 + k.360
x = 15 + k.60

k=0 — x = 15(tm)
k=1 — x = 75(tm)
k=2 — x = 135 (tm)
k=3 — x = 195
k=4 — x = 255
k=5 — x = 315
k=6 — x = 375
k=7 — x = 435
k=8 — x = 495
k=9 — x = 555
k=10 — x = 615
k=11 — x = 675
...
k=17 — x = 1035