(a)[4]
Find the distance separating the centres of the circles.
(b)[3]
$P$ and $Q$ are points on $C_1$ and $C_2$ respectively. The distance between $P$ and $Q$ is called $d$. Find the greatest and least possible values of $d$.
Mathematics 9709 · AS & A Level · Coordinate geometry
Coordinate geometry — practice question
The equations of circles $C_1$ and $C_2$ are $x^2 + y^2 + 6x - 10y + 18 = 0$ and $(x - 9)^2 + (y + 4)^2 - 64 = 0$, respectively.