Specimen 2020 Paper 1 Q11
11 A circle, centre \(C\), touches the \(y\)-axis at the point (0, 2)
The line \(\quad y = k \quad\) intersects the circle at the points \((1, k)\) and \((5, k)\)
Not drawn accurately
Work out the equation of the circle. [3 marks]
| Answer | Mark | Comments |
|---|---|---|
| (\(x\)-coordinate of \(C\) =) \(\dfrac{5 + 1}{2}\) or 3 or (radius =) \(\dfrac{5 + 1}{2}\) or 3 | M1 | may be implied |
| (\(y\)-coordinate of \(C\) =) 2 | M1 | may be implied |
| \((x - 3)^2 + (y - 2)^2 = 9\) | A1 | allow \((x - 3)^2 + (y - 2)^2 = 3^2\) |