Halliday, Resnick & Walker — Vectors: Problem 26

What is the sum of the following four vectors in (a) unit-vector notation, and as (b) a magnitude and (c) an angle? \[\vec{A} = (2.00 \text{ m})\hat{i} + (3.00 \text{ m})\hat{j} \quad \vec{B} = 4.00 \text{ m, at } +65.0^\circ\] \[\vec{C} = (-4.00 \text{ m})\hat{i} + (-6.00 \text{ m})\hat{j} \quad \vec{D} = 5.00 \text{ m, at } -235^\circ\]