June 2025 Paper 2 Q4
4 \(\quad -5 \leqslant n \leqslant 5\)
Work out the range of possible values of \(n^2\) [2 marks]
| Answer | Mark | Comments |
|---|---|---|
| \(0 \leqslant n^2 \leqslant 25\) | B2 | oe eg \(n^2 \leqslant 25\) and \(n^2 \geqslant 0\) B1 \(n^2 \leqslant 25\) or \(n^2 \geqslant 0\) SC1 \(0 \lt n^2 \lt 25\) oe SC1 \(0 \leqslant n \leqslant 25\) oe SC1 \(0 \leqslant \mathrm{f}(n) \leqslant 25\) oe |
Additional guidance
| B1 answers may be embedded eg1 \(0 \leqslant n^2 \lt 25\) eg2 \(-25 \lt n^2 \leqslant 25\) | B1 B1 |
| Accept equivalents throughout eg \(25 \geqslant n^2 \geqslant 0\) | B2 |
| B2 or B1 response in working with integer(s) on answer line is awarded B1 Condone integer(s) linked to \(n\) or \(n^2\) eg1 \(n^2 \leqslant 25\) in working Answer 1 2 3 4 5 eg2 \(0 \leqslant n^2 \leqslant 25\) in working Answer \(n^2 = 25\) | B1 B1 |
| Condone eg \(x\) used for \(n\) | |
| \(25 \leqslant n^2 \leqslant 25\) is choice | B0 |
| Accept interval notation throughout eg [0, 25) | B1 |