4MA0 Foundation January 2015 Paper 2R Q21
21 Here are some rows of a number pattern.
| Row number | Column 1 | Column 2 | Column 3 |
|---|---|---|---|
| 1 | 1 × 3 + 1 | 4 | \(2^2\) |
| 2 | 2 × 4 + 1 | 9 | \(3^2\) |
| 3 | 3 × 5 + 1 | 16 | \(4^2\) |
| ⋮ | ⋮ | ⋮ | ⋮ |
| 8 | |||
| ⋮ | ⋮ | ⋮ | ⋮ |
| \(n\) |
(a) Complete Row number 8 (2)
(b) Write down the Row number of the row that has 400 in Column 2 (1)
(c) For Row number \(n\),
(i) write down an expression, in terms of \(n\), that should go in Column 1
(ii) write down an expression, in terms of \(n\), that should go in Column 3
(2)| Scheme | Marks |
|---|---|
| 8 × 10 + 1, 81, \(9^2\) | B2 |
| (2) |
Notes
B2: All three correct
(B1 two correct)
| Scheme | Marks |
|---|---|
| 19 | B1 |
| (1) |
Notes
B1: cao
| Scheme | Marks |
|---|---|
| (i) \(n(n + 2) + 1\) | B1 |
| (ii) \((n + 1)^2\) | B1 |
| (2) | |
| (5 marks) |
Notes
B1: for \(n(n + 2) + 1\) on answer line or in table
B1: for \((n + 1)^2\) on answer line or in table
SC : If no marks scored in (i) or (ii) award B1 for \(n^2 + 2n + 1\) in (b)