Using the definition of the scalar product, find the angles between the following pairs of vectors.

Question

A = - 4 i + 2 j + 2 k and B = - 3 j - 3 k

I understand to do [(A).(B)]/|A|*|B| = cos theta; but I'm getting 0 for |A| and don't know how to access it from there.

Answer 1

never mind, found the mistake I was making.

Answer 2

I AM NOT ABLE TO FIND ANGLE