Question

Show that the sequence defined by a_n = 3n² − 5 is not an A.P.

Answer 1

In the given problem, we need to show that the given sequence is not an A.P

Here,

Now, first we will find its few terms by substituting

So,

Substituting n = 1, we get

Substituting n = 2, we get

Substituting n = 3, we get

Substituting n = 4, we get

Substituting n = 5, we get

Further, for the given sequence to be an A.P,

We find the common difference (d)

Thus,

Also,

So,

Hence, the given sequence is not an A.P.