diketahi cos x = 0,2 dan x lancip. Tentukan Nilai sin ( x - 30 ). TOlong yang Bisa ngerjakan!

Bab Trigonometri
Matematika SMA Kelas X

0,2 = 2/10 = 1/5

sin x = √(1 - cos² x)
sin x = √(1 - (1/5)²)
sin x = √(25/25 - (1/25))
sin x = √(24/25)
sin x = (2/5) √6

sin (x - 30°)
= sin x . cos 30° - cos x . sin 30°
= (2/5) √6 . (1/2) √3 - (1/5) . (1/2)
= (2/10) . √18 - 1/10
= (2/10) . 3√2 - 1/10
= (1/10) . (6√2 - 1)