Question

The suitable formula to find the sum of first n terms of the AP 1 + 3 + 5 + 7 +......... is ...........

Answer 1

Answer:

(2n^2 +n)/2

Step-by-step explanation:

1+3+5+7....

a=1

d=2

sum of n terms= n/2{2a+(n-1)d}

= n/2{2+2(n-1)}

=n/2(2+2n-1)

=n/2(2n+1)

=n^2 + n/2

=  2n^2+n /2