| Exam Board | OCR MEI |
|---|---|
| Module | C2 (Core Mathematics 2) |
| Year | 2007 |
| Session | January |
| Marks | 3 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Geometric Sequences and Series |
| Type | Find specific nth term |
| Difficulty | Moderate -0.8 This is a straightforward C2 question testing basic sequence recognition and formula application. Parts (i) and (ii) require simple pattern identification, while part (iii) asks for the nth term of a geometric sequence with clear common ratio 2, requiring only the standard formula u_n = ar^(n-1). No problem-solving or novel insight needed—purely routine application of core concepts. |
| Spec | 1.04e Sequences: nth term and recurrence relations1.04f Sequence types: increasing, decreasing, periodic |
| Answer | Marks |
|---|---|
| C | B1 |
| Answer | Marks |
|---|---|
| B | B1 |
| Answer | Marks |
|---|---|
| \(2^{n-1}\) | B1 |
## Question 4(i):
C | B1 |
## Question 4(ii):
B | B1 |
## Question 4(iii):
$2^{n-1}$ | B1 |
---4 Sequences $\mathrm { A } , \mathrm { B }$ and C are shown below. They each continue in the pattern established by the given terms.
$$\begin{array} { l l l l l l l l l }
\text { A: } & 1 , & 2 , & 4 , & 16 , & 32 , & \ldots & \\
\text { B: } & 20 , & - 10 , & 5 , & - 2.5 , & 1.25 , & - 0.625 , & \ldots \\
\text { C: } & 20 , & 5 , & 1 , & 20 , & 5 , & 1 , & \ldots
\end{array}$$
(i) Which of these sequences is periodic?\\
(ii) Which of these sequences is convergent?\\
(iii) Find, in terms of $n$, the $n$th term of sequence A .
\hfill \mbox{\textit{OCR MEI C2 2007 Q4 [3]}}