Nilai dari cos 45°.sin 15°
Jawaban Terkonfirmasi
Kelas 10 Matematika
Bab Trigonometri
cos 45° . sin 15°
= 1/2 √2 . (sin (45° – 30°))
= 1/2 √2 . (sin 45° . cos 30° – cos 45° . sin 30°)
= 1/2 √2 . (1/2 √2 . 1/2 √3 – 1/2 √2 . 1/2)
= 1/2 √2 . (1/4 √6 – 1/4 √2)
= 1/8 √12 – 1/8 . 2
= 1/8 √2 – 1/4
= 1/4 (2√2 – 1)