Higher June 2017 Paper 2 Q22
22 Here are the first five terms of a sequence.
4 11 22 37 56
Find an expression, in terms of \(n\), for the \(n\)th term of this sequence. (3)
| Answer | Mark | Notes |
|---|---|---|
| \(2n^2 + n + 1\) | M1 | for a correct start to a method to find \(n\)th term, eg. equal 2nd differences imply a term in \(n^2\) or sight of \(an^2 + bn + c\) |
| M1 | for a method leading to \(2n^2\) and either \(n\) or 1 | |
| A1 | for \(2n^2 + n + 1\) oe |