Question

How do you find unit vector of `a=(1, 2, -2)` in direction of `a`?

Answer 1

`a/(|| a ||) = (1/3, 2/3, -2/3)`

Explanation:

Divide by the length of the vector `a`.

`|| a || = sqrt(1^2+2^2+(-2)^2) = sqrt(1+4+4) = sqrt(9) = 3`

So the unit vector is:

`a/(|| a ||) = 1/3(1, 2, -2) = (1/3, 2/3, -2/3)`