Find the magnitude and direction angle (to the nearest tenth) for each vector. Give the measure of the direction angle as
an angle in [0,360°].
-$\langle - 4 , - 3 \rangle$
A) $5 ; 233.1 ^ { \circ }$
B) $5 ; 216.9 ^ { \circ }$
C) $5 ; 36.9 ^ { \circ }$
D) $7 ; 216.9 ^ { \circ }$

Question

Quizplus · Accepted Answer

The magnitude of the vector $\langle -4, -3 \rangle$ is $\sqrt{(-4)^2 + (-3)^2} = 5$. The direction angle is found using $\tan^{-1}(\frac{-3}{-4})$, which gives an angle in the first quadrant. Since the vector is in the third quadrant, add 180° to get 216.9°.

Find the Magnitude and Direction Angle (To the Nearest Tenth) ⟨−4,−3⟩\langle - 4 , - 3 \rangle⟨−4,−3⟩

Find the Magnitude and Direction Angle (To the Nearest Tenth) $\langle - 4 , - 3 \rangle$