Question

56. Sum of nterm of the series1+3+5+7+9..... is:​

Answer 1

Given:-

a = 1

d = 2

To find :-

sum of nth term

Solution:-

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

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

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

Sn = n/2(2n)

Sn = n²