4MA0 Higher June 2012 Paper 4 Q10
10
(a) Expand and simplify
(i) \(5(2x + 1) - 3(3x - 1)\)
(ii) \((y + 5)(y - 7)\)
(4)(b) Make \(r\) the subject of the formula \(V = \pi r^2 h\) where \(r\) is positive. (2)
| Scheme | Marks |
|---|---|
| (i) \(10x + 5 - 9x + 3\) Answer: \(x + 8\) | B2 |
| (ii) \(y^2 + 5y - 7y - 35\) Answer: \(y^2 - 2y - 35\) | B2 |
| (4) |
Notes
B2: B1 for 3 correct terms with correct signs or 4 correct terms ignoring signs
B2: B1 for 3 correct terms with correct signs or 4 correct terms ignoring signs
N.B. \(-2y\) (with no more \(y\) terms) implies \(+5y - 7y\)
Apart from questions 5, 7, 13c, 16b, 20, 21 and 22 (where the mark scheme states otherwise) the correct answer, unless clearly obtained by an incorrect method, should be taken to imply a correct method.
| Scheme | Marks |
|---|---|
| \(V / \pi h = r^2\) (oe) | M1 |
| \(\sqrt{\dfrac{V}{\pi h}}\) oe | A1 |
| (2) | |
| (Total 6 marks) |
Notes
M1: isolating \(r^2\) (must be correct equation).
A1: condone ± Allow \(\sqrt{V} \div \sqrt{\pi} \div \sqrt{h}\) etc