vectors! :)

[ald942]

Hi guys.Iv been looking over notes but cant get going with this questio at all.Anyhelp will be appreaciated.Cheers.

Given that the vector A=2i +3j+-4k and the vector B=-i+2j+5k calculate a unit vector in the direction of A(the vector A) and a unit vector in the direction of B(the vector B).

 

[galactus]

Normalize A and get \(\displaystyle \sqrt{2^{2}+3^{2}+(-4)^{2}}=\sqrt{29}\)

\(\displaystyle \frac{1}{\sqrt{29}}\)

There's a start.

 

[ald942]

thats a start anyway...Sound.

 

[galactus]

A unit vector is just a vector of length 1.

To find this unit vector, mormalize as I showed you in the last post, then multiply by the vector.

\(\displaystyle \frac{1}{\sqrt{29}}[2,3,-4]=\frac{2}{\sqrt{29}}i+\frac{3}{\sqrt{29}}j-\frac{4}{\sqrt{29}}k\)