Question

Tentukan nilai sin, cos, tan pada:
Sin π/12
Cos 5π / 8

Answer 1

1. 0,258819
2. 0,382683

Answer 2

Nilai π = 180°

Jadi,
1). Sin π/12 = 180°/12 = 15°

Sin 15° = Sin(45° - 30°)
Sin 15° = sin45°.cos30 - cos45°.sin30°
Sin 15° = 1/2√2.1/2√3 - 1/2√2.1/2
Sin 15° = 1/4√6 - 1/4√2
Sin 15° = 1/4(√6 - √2)

2). Cos 5π/6 =  5.180/6 = 150°

Cos 150° = -1/2√3