TITLE: How to think of $\vec{u}-\vec{v}$
QUESTION [9 upvotes]: Assume I have two vectors, $\vec{u}$ and $\vec{v}$. I know that I can think of their sum via Triangle or Parallelogram Law, but I'm having trouble knowing which way the vector would point depending on if it was $\vec{u}-\vec{v}$ or if it was $\vec{v}-\vec{u}$. Is there an easy way to remember which way the arrow would point?

REPLY [5 votes]: Remember that $\vec{u}-\vec{0}=\vec{u}$ is the vector from the origin to $\vec{u}$. This reminds me that $\vec{u}-\vec{v}$ is in the direction from $\vec{v}$ to $\vec{u}$.