Question

The sum of first n terms of an ap is given by sn = 3n square _n find its nth term and first term and common difference

Answer 1

i think this is your answer

Answer 2

Answer:

The first term is a=2.

The common difference is 6.

The nth term of the sequence is $a_n=6n-4$

Step-by-step explanation:

Given : The sum of first n terms of an A.P is given by $S_n=3n^2-n$

To find : Its nth term and first term and common difference ?

Solution :

The sum of first n terms of an A.P is given by $S_n=3n^2-n$

If we put n=1 we get sum of first term i.e. first term,

$S_1=3(1)^2-(1)$

$S_1=2$

The first term is a=2.

If we put n=2 we get sum of first two term,

$S_2=3(2)^2-(2)$

$S_2=10$

$a_1+a_2=10$

$2+a_2=10$

$a_2=8$

The second term is 8.

The common difference is $d=a_2-a_1$

$d=8-2$

$d=6$

The common difference is 6.

The nth term of the sequence is $a_n=a+(n-1)d$

$a_n=2+(n-1)6$

$a_n=2+6n-6$

$a_n=6n-4$

The nth term of the sequence is $a_n=6n-4$