Thread: Vector Derivation

I've been looking at this problem for awhile and it seems impossible, but I know there's probably an easy solution. Can anyone give me a hint in the right direction?

Thanks in advance ( yes, i'll click the thanks button for you )

Ponder the formulation for the Projection of a vector onto another vector.

It may help to move those |B| things inside the parentheses so it looks more like a Unit Vector inside there.