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5 votes
Find the angle between the given vectors to the nearest tenth of a

degree.
U = 13i - 8j V = 2i + 9j

User Pramit
by
4.9k points

1 Answer

4 votes

Answer: 109.1 degrees

Explanation:

To find the angle between the given vectors, we will use the formula below:

Cos(θ) = (U.V)/ |U|.|V|

Where

U = 13i - 8j

V = 2i + 9j

U.V = (2x13) + (-8×9)

U.V = 26 - 72

U.V = - 46

|U| = sqrt ( 13^2 + 8^2)

= sqrt ( 233) = 15.264

|V| = sqrt( 2^2 + 9^2)

= sqrt ( 85 ) = 9.22

Substitute all the value of the parameters into the formula

Cos ø = -46 / (15.3 × 9.2)

Cos ø = - 46 / 140.72

Cos Ø = - 32687

Find the cos inverse of the value

Ø = cos^-1( -32687)

Ø = 109.079 degrees

Therefore, the angle between the given vectors to the nearest tenth of a degree is 109.1 degrees

User Mary
by
4.4k points