Question

Solve if the sum of n term of an ap is given by sn = 3n squire+4n . determine the ap and the nth term

Answer 1

here is your answer....!

Answer 2

Hey there !!

Let a be the first term d be the common difference and n be the number of term

given that -

$sn \: = {3n}^{2} + 4n$
If n = 1 then

$\: = 3 \times {1}^{2} + 4 \times 1 \\ \\ = 7$
If n = 2 then


$= 3 \times 2 \times 2 + 4 \times 2 \\ \\ = 20$
$now \: \\ \: a2 \: = S2 - S1 \\ \\ = 20 - 7 = 13$
d = 13 - 7

= 6

So ur requirred AP is -

7 , 13 , 19 .....

nth term = 7 + ( n-1) 6

= 7 + 6n -6

= 1 + 6 n



Hope this helps u !!