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5 votes
5 votes
Math v

i need help pls!!





what’s the answer

Math v i need help pls!! what’s the answer-example-1
User Adneal
by
2.4k points

1 Answer

12 votes
12 votes

Answer: 35/4

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Step-by-step explanation:

Consider these two general vectors in R2

v = <a, b>

w = <c, d>

The dot product of them is

v dot w = a*c+b*d

If the dot product is zero, then the vectors are perpendicular, aka orthogonal.

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In this problem we have

v = <-7, -4>

w = <-5, k>

The idea is to take the dot product of these items and set the result equal to zero. Then isolate k.

v dot w = 0

(-7)*(-5) + (-4)*k = 0

35 - 4k = 0

4k = 35

k = 35/4