Use the dot product to find $ |\mathbf{v}| $
-$$\mathbf { v } = \langle - 2 , - 1 \rangle$$
A) $- 3$
B) $\sqrt { 3 }$
C) $- 1$
D) $\sqrt { 5 }$

Question

Quizplus · Accepted Answer

The magnitude of a vector $\mathbf{v} = \langle a, b \rangle$ is given by $|\mathbf{v}| = \sqrt{a^2 + b^2}$. For $\mathbf{v} = \langle -2, -1 \rangle$, $|\mathbf{v}| = \sqrt{(-2)^2 + (-1)^2} = \sqrt{4 + 1} = \sqrt{5}$.

Use the Dot Product to Find ∣v∣ |\mathbf{v}| ∣v∣ - v=⟨−2,−1⟩\mathbf { v } = \langle - 2 , - 1 \ranglev=⟨−2,−1⟩

Use the Dot Product to Find $|\mathbf{v}|$ - $\mathbf { v } = \langle - 2 , - 1 \rangle$