8 litres of paint can cover 129.6 m². How much paint is required to paint an area of 243m²?
1 answer:
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Answer:
49°
Step-by-step explanation:
Given vectors:
a = [-8, 6]
B = [√7, 3]
θ = ?
To find the angle between the two vectors, we will be using the formula,
a.B = |a||B|cosθ
For simplicity, it is good to first calculate the dot product, and the magnitudes. Then we will substitute the values of the dot product, and the magnitudes of the vectors to solve for the angle.
Calculating the dot product
a.B = (-8, 6) . (√7, 3)
= (-8 × √7) + (6 × 3)
= -8√7 + 18
= 18 - 8√7
= 10√7
Calculating the magnitude the vectors
1. The magnitude of vector (-8, 6)
2. The magnitude of vector (√7, 3)
Calculating the angle between the vectors,
cosθ =
cosθ =
cosθ = 0.6614
θ = cos⁻¹0.6614
θ = 48.59°
θ = 49°