Question

NO LINKS OR ELSE YOU'LL BE REPORTED!Only answer if you're very good at Math.

Let u= (5,-12) and c=-3.What is ||cu||?

A: -39

B: 21

C: 39

D: 51​

Answer 1

Answer: C) 39

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Work Shown:

u = (5, -12)

cu = c*(5,-12)

cu = (5c, -12c)

cu = (5*(-3), -12*(-3))

cu = (-15, 36)

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Now we'll use the idea that if u = (a,b), then |u| = sqrt(a^2+b^2)

So this means,

cu = (-15, 36)

|cu| = sqrt( (-15)^2 + (36)^2 )

|cu| = sqrt(1521)

|cu| = 39

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Note how vector u = (5,-12) has magnitude 13 after applying that formula above. We have a 5-12-13 right triangle. If we triple each side, then the 5-12-13 becomes 15-36-39

Tripling the components of the vector means the length of the vector has been tripled.

Answer 2

Option C: 39

Explanation:

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