Question

Find the sum 1+(1+2)+(1+2+3)+......to n terms of the series

Answer 1

hii

here is ur solution


given that,

1 + 3 + 6 + ............... nth

a = 1

d = a2 - a1

d = 3 - 1 = 2
and a3 - a2

d 6 - 3 = 3


In the given question the common difference are not equal, hence it is not an AP so we can not find the sum of nth term.

hope it helps you