The nth term of a sequence is 3n–2. Is the sequence an A.P. ? If so, find its 10th term.
We have, an=3n–2
Clearly an is a linear expression in n. So, the given sequence is an A.P. with common difference 3.
(or)
an=3n–2
⇒a1=3(1)–2=1
a2=3(2)–2=4
a3=3(3)–2=7
a3−a2=7−4=3a2−a1=4−1=3
i.e., the difference of consecutive terms is constant.
So, an=3n–2 will form an A.P.
Putting n=10, we get
a10=3×10–2=28
Therefore, 10th term is 28.