Question

(v) The sum of the first n terms of an AP is
Sn=____​

Answer 1

The sum of first n terms of an AP is

n[ 2a + ( n - 1 )d ] / 2

Thank you.

( It was first used by Mathematician Federal Karl Gauss )

Answer 2

Answer:

Sn = n/2 [ 2a + (n-1)d ]

where a = first term

d = common difference

n = number of terms

Hope it helps you:)