Higher June 2018 Paper 4 Q19
19 Here are the first four terms of a quadratic sequence.
0 9 22 39
The \(n\)th term can be written as \(an^2 + bn + c\).
Find the values of \(a\), \(b\) and \(c\). [4]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| [\(a\) = ] 2 [\(b\) = ] 3 [\(c\) = ] −5 | 4 | B2 for [\(a\) =] 2 or M1 for second differences = 4 and M1 for revised differences of −2 1 4 7 or B1 for \(b\) or \(c\) correct | |