Answer
As a result we get $\frac{1}{9}\langle8,-1,4\rangle$.
Work Step by Step
We are given $\langle8,-1,4\rangle$. In order to make this a unit vector we need to scale this vector by $\frac{1}{|\langle8,-1,4\rangle|}$.
$|\langle8,-1,4\rangle|=\sqrt{(8)^2+(-1)^2+(4)^2}=\sqrt{81}\Rightarrow\frac{1}{9}\langle8,-1,4\rangle$
