Question

in an AP of n terms ,if the last term is negative of first term ,then the sum of n terms of the AP is

Answer 1

we know that sum of n terms is Sn=n/2[a+l]
where l = last term
a=first term
given,
the last term is negative of first term
so let as assume first term=x
last term =-x
Sn =n/2[x-x]
Sn=0
I HOPE THIS WILL HELP U FRND

Answer 2

Define x:

Let the first term be x

The last term is negative of first term

⇒ The last term is -x

Sum of AP:

Formula: Sum = n/2 ( a1 + an)

Sub in a1 = x and an = -x:

Sum = n/2 ( x - x)

Sum = n/2 (0)

Sum = 0

Answer: The sum of the AP is zero