| Exam Board | SPS |
|---|
| Module | SPS SM (SPS SM) |
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| Year | 2021 |
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| Session | January |
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| Topic | Circles |
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7.
A circle whose centre is at \(( 3 , - 5 )\) has equation
$$x ^ { 2 } + y ^ { 2 } - 6 x + a y = 15$$
where \(a\) is a constant.
a) Find the value of \(a\).
b) Determine the radius of the circle.