Question

pls solve it.......



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Answer 1

HEY THERE!!!


Question:

if the sum of first n terms of an ap is given by sn=3n²+2n find the nth term?

Method Of Solution:


Let to first term of Arithmetic Sequence or Progression 'a'.

Let to common Difference of Arithmetic Progression 'd' and it's nth terms be 'n'

Here, n denotes 'Number Of terms of Arithmetic Sequence or Progression".

According to the Question;

Given:

Sequence:

Sn = 3n²+2n



To find = nth term ?

Here,

Using Formula of Tn

Formula: Tn = Sn-1 - Sn

Substitute the value of n replace n-1

Tn= Sn-1 - Sn

=> 3n²+2n

=> 3(n-1)²+2(n-1) - (3n²+2n)

=> 3(n²+1-2n)+2n-2 -( 3n²+2n)

=> 3n²+3-6n+2n-2 -3n²-2n

=> -6n-2n+2n+3-2

=> -8n+2n+1

=> -6n+1

=> 1-6n

Hence, rth term = 6n-1