Answer
$ \vec {AB}=\lt 3,1 \gt$
Work Step by Step
Find vector for $ \vec {AB}$
$ \vec {AB}=\lt x_2-x_1,y_2-y_1$
$ \vec {AB}=\lt 1-(-2),2-1 \gt$
$ \vec {AB}=\lt 3,1 \gt$
The equivalent representation starting at the origin is a vector from point $(0,0)$ to the point $\lt 3,1 \gt$.
