(i) tn = 4n – 3 (1 mark)
Sol. tn = 4n – 3
∴ t1 = 4 (1) – 3 = 4 – 3 = 1
∴ t2 = 4 (2) – 3 = 8 – 3 = 5
∴ t3 = 4 (3) – 3 = 12 – 3 = 9
∴ t4 = 4 (4) – 3 = 16 – 3 = 13
∴ t5 = 4 (5) – 3 = 20 – 3 = 17
∴ The first five terms of the sequence are 1, 5, 9, 13 and 17.