Question

1. If the sum of m terms of an A.P. is 3m2 + 4m, find the pth term.​

Answer 1

Answer:

s1=7

s2=20

t2=s2-s1

t2=13

a+2d=13

2d=6

d=3

tp=7+(p-1)3

tp=4+3p

Answer 2

Given

• Sm = 3m² + 4m,

To Find

• The pth term

Steps

S1 = 3 + 4 = a1 = 8

S2 = 12 + 8 = 20

and, S2 = a1 + a2

=> 20 = 7 + a2

=> a2 = 13

common diffrence d = a2 - a1 = 13 - 7 = 6

first term a = 7

an = a + (n - 1)d

now, put n = p

=> ap = 7 + (n - 1)6

=> ap = 6n + 1

Hence, pth term is 6n + 1.

$\rule{110}2$