Use the Dot Product to Find the Magnitude of U $\mathbf { u } = - 5 \mathbf { i } - 2 \mathbf { j }$

Multiple Choice

Use the dot product to find the magnitude of u if $\mathbf { u } = - 5 \mathbf { i } - 2 \mathbf { j }$

A) $\| \mathbf { u } \| =$ 10
B) $\| \mathbf { u } \| =$ $2 \sqrt { 29 }$
C) $\| \mathbf { u } \| = 7$
D) $\| \mathbf { u } \| = 15$
E) $\| \mathbf { u } \| =$ $\sqrt { 29 }$