hitunglah sin 45.sin 75 ------------------- sin 30 .cos 15

Mapel : Matematika
Kelas : X SMA
Bab : Trigonometri

Pembahasan :
Sin 75°
= Sin (90 - 15)°
= Cos 15°

(Sin 45 . Sin 75)/(Sin 30 . Cos 15)
= (Sin 45 . Cos 15)/(Sin 30 . Cos 15)
= (Sin 45°)/(Sin 30°)
= (1/2 √2)/(1/2)
= √2

trigonometri

{sin 45. sin 75) / ( sin 30 . cos 15) =
= (sin 45  sin(90-15)] / (sin 30 . cos 15)
= (sin 45 . cos 15)/ (sin 30 . cos 15) .....cos 15 coret
= sin 45/sin 30
= (1/2 √2) / (1/2)
= √2