(iv)
We have the nth term of a sequence as tn = n2 – 2n.
To find the first five terms of the sequence, we need to take n = 1, 2, 3, 4 and 5.
For n = 1, we have:
t1 = 12 – 2 × 1 = 1 – 2 = –1
For n = 2, we have:
t2 = 22 – 2 × 2 = 4 – 4 = 0
For n = 3, we have:
t3 = 32 – 2 × 3 = 9 – 6 = 3
For n = 4, we have:
t4 = 42 – 2 × 4 = 16 – 8 = 8
For n = 5, we have:
t5 = 52 – 2 × 5 = 25 – 10 = 15
Thus, the first five terms of the sequence are –1, 0, 3, 8 and 15.