Question

Tentukan nilai dari
4 cos 15° cos 75°

Answer 1

Verified answer

Bab Trigonometri
Matematika SMA Kelas X

4 . cos 15° . cos 75°
= 2 . 2 cos 15° . cos 75°
= 2 (cos (15 - 75)° + cos (15 + 75)°)
= 2 . (cos (-60)° + cos 90°)
= 2 . (1/2 + 0)
= 2 . 1/2
= 1