Find the Unit Vector Having the Same Direction as V $$v = - 3 i + j$$

Multiple Choice

Find the unit vector having the same direction as v.
- $$v = - 3 i + j$$

A) $\mathbf { u } = - \frac { 3 \sqrt { 10 } } { 10 } \mathrm { i } - \frac { \sqrt { 10 } } { 10 } \mathrm { j }$
B) $\mathbf { u } = - \frac { \sqrt { 10 } } { 3 } \mathbf { i } + \sqrt { 10 } \mathbf { j }$
C) $\mathbf { u } = - 3 \sqrt { 10 } \mathbf { i } + \sqrt { 10 } \mathbf { j }$
D) $\mathbf { u } = - \frac { 3 \sqrt { 10 } } { 10 } \mathbf { i } + \frac { \sqrt { 10 } } { 10 } \mathbf { j }$