TRIGONOMETRI 1. Cos α = -1/3 ,α kuadran 2 tan α = 2. sin 30° + cos 45° = 3. sin 30° + sin 60° / 1 - sin 45° = 4. sin² 150° = mohon bantuannya...

1. Cos α = -1/3 (samping/miring)
depan = √(samping^2-miring^2)
depan = √(3^2-(-1)^2)
depan = √(9-1)
depan = √8
depan = 2√2
Karena di kuadran 2 nilai tan adalah min (-)
tan α = -(depan/samping)
tan α = -(2√2/(-1))
tan α = 2√2
2. sin 30° + cos 45°
= 1/2 + √2/2
= 1/2(1+√2)
3. sin 30° + sin 60° / 1 - sin 45°
= (1/2 + √3/2) / (1 - √2/2)
= √2/2
4. sin150°² 150°
= (sin150°)²
= (sin(180-3)°)²
= (sin30°)²
= (1/2)²
= 1/4