Question

If Sn=3n²+n,find the A.P.​

Answer 1

this is the answer of the math

Answer 2

Solution:-

Given Equation:-

Sn = 3n² + n

Taking ( n = 1). we get,

=) S(1) = 3 × 1² + 1

=) S(1) = 4.

Hence,

First Term = a = 4.

Taking ( n=2). we get,

=) S(2) = 3 × 2² + 2

=) S (2) = 3× 4 + 2

=) S (2) = 14.

Now,

Second Term = Sum of First two term - First Term

=) Second Term= 14 - 4

=) Second Term = 10.

To Make the Term in A.P.

We should Find out the Common Difference (D), which is always constant.

=) D = Second Term - First Term

=) D = 10 - 4

=) D = 6.

=) Common Difference = 6.

Hence,

The A.P. is 4, 10, 16, 22, 28,...........