(a)[4]
Find, using calculation, the coordinates of $A$ and $B$.
(b)[4]
Find an equation of the circle with centre at $C$ for which the line with equation $y = 3x - 20$ is tangent to the circle.
Mathematics 9709 · AS & A Level · Coordinate geometry
Coordinate geometry — practice question
In the diagram, the circle has equation $(x + 1)^2 + (y - 2)^2 = 85$ and the straight line has equation $y = 3x - 20$. The line cuts the circle at $A$ and $B$, and the centre of the circle is $C$.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Replace the line equation in the circle equation to form a quadratic” …
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