| Date | November 2014 | Marks available | 2 | Reference code | 14N.1.sl.TZ0.2 |
| Level | SL only | Paper | 1 | Time zone | TZ0 |
| Command term | Find | Question number | 2 | Adapted from | N/A |
Question
In an arithmetic sequence, the first term is \(2\) and the second term is \(5\).
Find the common difference.
Find the eighth term.
Find the sum of the first eight terms of the sequence.
Markscheme
correct approach (A1)
eg\(\;\;\;d = {u_2} - {u_1},{\text{ }}5 - 2\)
\(d = 3\) A1 N2
[2 marks]
correct approach (A1)
eg\(\;\;\;{u_8} = 2 + 7 \times 3\), listing terms
\({u_8} = 23\) A1 N2
[2 marks]
correct approach (A1)
eg\(\;\;\;{S_8} = \frac{8}{2}(2 + 23)\), listing terms, \(\frac{8}{2}\left( {2(2) + 7(3)} \right)\)
\({S_8} = 100\) A1 N2
[2 marks]
Total [6 marks]
Examiners report
All three parts of this question were very well done by the candidates. The occasional mistakes that were seen tended to be arithmetic errors which happened after the candidates had substituted correctly into the formulas given in the formula booklet.
All three parts of this question were very well done by the candidates. The occasional mistakes that were seen tended to be arithmetic errors which happened after the candidates had substituted correctly into the formulas given in the formula booklet.
All three parts of this question were very well done by the candidates. The occasional mistakes that were seen tended to be arithmetic errors which happened after the candidates had substituted correctly into the formulas given in the formula booklet.
