Unit Vector

Example :

The vector $\stackrel{\to }{PQ}$ has initial point at $P(1,1)$ and terminal point at $Q(1.6,1.8)$ .

$\begin{array}{l}\left|\stackrel{\to }{PQ}\right|=\sqrt{{(1.6-1)}^2+{(1.8-1)}^2}\\ =\sqrt{{0.6}^2+{0.8}^2}\\ =\sqrt{0.36+0.64}\\ =\sqrt{1}\\ =1\end{array}$

The magnitude of $\stackrel{\to }{PQ}$ is $1$ . So, $\stackrel{\to }{PQ}$ is a unit vector.