4MA0 Higher June 2014 Paper 3R Q19
19 Solve the inequality \(\;3x^2 + 5 \lt 53\)
(3)
| Scheme | Marks |
|---|---|
\(x^2 \lt \dfrac{53 - 5}{3}\) or \(x^2 \lt \dfrac{48}{3}\) or \(3(x^2 - 16) \lt 0\) | M1 |
| M1 | |
| \(-4 \lt x \lt 4\) | A1 |
| (3) | |
| (3 marks) |
Notes
M1: Allow \(x^2 = 16\) oe.
\(3(x^2 - 16) = 0\)
M1: For – 4 and 4
A1: for correct inequality
accept \(-4 \lt x\) and \(x \lt 4\)