tolong ya jawab mtk minat kelas 10 yg no 11 mksh

OA = i + 2j = (1, 2)
OB = 4i + j = (4, 1)

Sudut antara OA dan OB adalah Φ

Gunakan rumus
Cos Φ = OA × OB / |OA| × |OB|

Cari OA × OB
(1, 2) × (4, 1) = 4 + 2 = 6

|OA| = √(1)² + (2)² = √5
|OB| = √(4)² + (1)² = √17

Cos Φ = (6) / √5 × √17
Cos Φ = 6 / √85

= √(√85)² - 6²
= √85 - 36
= √49
= 7

Nilai tan Φ = 7/6