Question:
If the nth term an of a sequence is given by an = n2 − n + 1, write down its first five terms.
Solution:
Given : $a_{n}=n^{2}-n+1$
For $n=1, a_{1}=1^{2}-1+1$
= 1
For $n=2, a_{2}=2^{2}-2+1$
= 3
For $n=3, a_{3}=3^{2}-3+1$
= 7
For $n=4, a_{4}=4^{2}-4+1$
= 13
For $n=5, a_{5}=5^{2}-5+1$
= 21
Thus, the first five terms of the sequence are 1, 3, 7, 13, 21.