Foundation June 2017 Paper 2 Q25
25 Here are the first six terms of an arithmetic sequence.
3 8 13 18 23 28
(a) Find an expression, in terms of \(n\), for the \(n\)th term of this sequence. (2)
The \(n\)th term of a different sequence is \(3n^2\)
Nathan says that the 4th term of this sequence is 144
(b) Is Nathan right?
Show how you get your answer. (1)
Show how you get your answer. (1)
| Answer | Mark | Notes |
|---|---|---|
| \(5n - 2\) | B2 | for \(5n - 2\) oe |
| [B1 | for \(5n + k\), \(k\) may be 0] |
| Answer | Mark | Notes |
|---|---|---|
| No (supported) | C1 | for No with evidence, e.g. \(3 \times 4^2 = 48\), \(\sqrt{48}\) is not an integer, he has multiplied by 3 first but should have squared first |