(a(i))[2]
Find $\vec{PQ}$.
(a(ii))[3]
Show that $|\vec{OP}| = |\vec{OQ}|$.
(a(iii))[2]
Calculate the circumference of this circle.
(a(iv))[2]
Find the coordinates of $R$.
(a(v))[4]
Find the equation of the perpendicular bisector of $PQ$. Give your answer in the form $y=mx+c$.
(b)[4]
In terms of $\mathbf{a}$ and $\mathbf{b}$, find the position vector of $M$.