Chapter 11 - Vectors and Vector-Valued Functions - 11.1 Vectors in the Plane - 11.1 Exercises - Page 767: 8

For $P(x,y),Q(z,t)$, $\overrightarrow{PQ}(z-x,t-y)$

Let $P(x,y)$ and $Q(z,t)$ be two points. The $x$-component of $\overrightarrow{PQ}$ is the difference in the $x$-coordinates of $Q$ and $P$ (which is $z-x$), while the $y$-component of $\overrightarrow{PQ}$ is the difference in the $y$-coordinates of $Q$ and $P$ ($t-y$). Therefore $\overrightarrow{PQ}(z-x,t-y)$.