Find the projection of $U$ onto $V$?

Question

I'm really stuck on this precalc problem: Find the projection of $u$ onto $v$ if $u=(-3,3)$ and $v=(-2,5)$.

Answer 1

We have: $\text{proj}\vec{u}_\vec{v} = \left(\dfrac{\vec{u}\cdot \vec{v}}{||\vec{v}||^2}\right)\vec{v} = \dfrac{(-3)(-2)+3\cdot 5}{(-2)^2+5^2}\left(-2,5\right) = \left(\dfrac{-42}{29},\dfrac{105}{29}\right)$.

Answer 2

You should have a formula to the effect of $$ \text{proj}_v(u) = \frac{u \cdot v}{v \cdot v} v $$