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a) Let vector x be the vector of length 9 and in the same direction as vector u=...

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gomezzzzzzzzz... | Student | (Level 1) Honors

Posted January 15, 2013 at 11:16 PM via web

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a) Let vector x be the vector of length 9 and in the same direction as vector u= <-4,-1>

What is vector x equal to?

 

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mlehuzzah | Student, Graduate | (Level 1) Associate Educator

Posted January 15, 2013 at 11:34 PM (Answer #1)

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Vector u has length:

`sqrt((-4)^2+(-1)^2)=sqrt(16+1)=sqrt(17)`

We want a vector of length 9 in the same direction.  Thus, we must multiply each entry of u by `9/sqrt(17)`

This gives the vector:

`<(-36)/sqrt(17),(-9)/sqrt(17)>` which simplifies to

`<(-36 sqrt(17))/17, (-9 sqrt(17))/17 >`

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