(i) 3, 1, −1, −3 … First term, a = 3 Common difference, d = Second term - First term d = 1 − 3 d = −2
(ii) −5, −1, 3, 7 … First term, a = −5 Common difference, d = Second term - First term d = (−1) − (−5) d = − 1 + 5 d = 4
(iii) \(\frac{1}{3}, \frac{5}{3} , \frac{9}{3}, \frac{13}{3}\) ,… First term, a = \(\frac{1}{3}\) Common difference, d = Second term - First term \(\text{d}=\frac{5}{3} - \frac{1}{3}\) \(\text{d} = \frac{4}{3}\)
(iv) 0.6, 1.7, 2.8, 3.9 … First term, a = 0.6 Common difference, d = Second term - First term d = 1.7 − 0.6 d = 1.1
| a | d | n | \(a_n\) | |
| (i) | 7 | 3 | 8 | …. |
| (iI) | -18 | … | 10 | 0 |
| (iii) | … | -3 | 18 | -5 |
| (iv) | -18.9 | 2.5 | … | 3.6 |
| (v) | 3.5 | 0 | 105 | … |