4400 Higher June 2009 Paper 3 Q9
9

Diagram NOT accurately drawn
\(A\) is a point on a circle with centre \(O\) and radius 4.7 cm.
\(AB\) is the tangent to the circle at \(A\).
\(AB = 5.9\) cm.
\(OB\) intersects the circle at \(C\).
Calculate the length of \(BC\).
Give your answer correct to 3 significant figures.
(4)
| Scheme | Marks |
|---|---|
| \(4.7^2 + 5.9^2\) \(= 22.09 + 34.81 = 56.9\) | M1 |
| \(\sqrt{4.7^2 + 5.9^2}\) | M1 |
| 7.5432... | A1 |
| 2.84 | A1 |
| (4) | |
| (4 marks) |
Notes
M1: for squaring & adding
M1: (dep) for square root
A1: for value which rounds to 7.54
A1: for answer which rounds to 2.84 (2.84320...)