1.4: Vectors from a direction and from an angle

0606/12/M/J/17 — Question 3 · 4 marks

Vectors i\mathbf{i} and j\mathbf{j} are unit vectors parallel to the xx-axis and yy-axis respectively.
(a)
The vector v\mathbf{v} has a magnitude of 353\sqrt{5} units and has the same direction as i2j\mathbf{i} - 2\mathbf{j}. Find v\mathbf{v} giving your answer in the form ai+bja\mathbf{i} + b\mathbf{j}, where aa and bb are integers.
[2]
(b)
The velocity vector w\mathbf{w} makes an angle of 30°30\degree with the positive xx-axis and is such that w=2|\mathbf{w}| = 2. Find w\mathbf{w} giving your answer in the form ci+dj\sqrt{c}\,\mathbf{i} + d\mathbf{j}, where cc and dd are integers.
[2]