Mathematics 9709 · AS & A Level · Coordinate geometry
Coordinate geometry — practice question
The diagram depicts a curve with a maximum point at $(8, 12)$ and a minimum point at $(8, 0)$. This curve is obtained by applying two transformations to a circle. The first transformation is a translation of $\begin{pmatrix} 7 \\ -3 \end{pmatrix}$. The second transformation is a stretch in the $y$-direction.
(a)[1]
State the scale factor for the stretch.
(b)[1]
State the original circle’s radius.
(c)[2]
State the coordinates of the circle’s centre once the translation has been carried out, but before the stretch is applied.
(d)[2]
State the coordinates of the original circle’s centre.
Worked solution & mark scheme
This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Gives answer $3$” …