Berapa hasil dari= cos 135° + cos 15°/ sin 195° + sin 45°

Materi : Trigonometri Rangkap
Kelas : X

cos 135° + cos 15° / sin 195° + sin 45°
= 2 cos 1/2 (135°+15°) cos 1/2 (135°-15°) / 2 sin 1/2 (195°+45°) cos 1/2 (195° - 45°)
= 2 cos 1/2 (150°) cos 1/2 (120°) / 2 sin 1/2 (240°) cos 1/2 (150°)
= 2 cos 75° cos 60° / 2 sin 120° cos 75°
= 2 cos 75° . 1/2 / 2 (1/2) cos 75°
= 2 cos 75 . 1/2 / cos 75°
= cos 75° / cos 75°
= 1