Answer:
Step-by-step explanation:
Given the pair vector
U = (4, 5) = 4•i + 5•j
V = (-4, -1) = -4•i - 1•j
Then,
The angle between two vectors can be determined using
U•V = |U||V| Cosθ
|U| = √(4²+5²) = √(16 + 25) = √41
|V| = √(-4)²+(-1)² =√(16 + 1) = √17
U•V = |U||V| Cosθ
(4•i + 5•j)•(-4•i - 1•j) = √41 × √17 Cosθ
-16 - 5 = √(41×17) Cosθ
-21 = √697 Cosθ
Cosθ = -21 / √697
Cosθ = -0.7954
θ = Arccos(-0.7954)
θ = 142.7°.
