Question

4. Find the sum of the first as odd natural number​

Answer 1

Step-by-step explanation:

Hence this series is an Arithmetic Progression. First term of this sequence is 1 and the common difference is 2. So we get our sequence is arithmetic progression with a = 1 and d = 2. Hence the sum of the first n odd natural number is $n^2$.

Answer 2

Step-by-step explanation:

We have to find sum of the series : 1+3+5+... to n terms

Clearly, terms of the given series form an AP with first term a=1 and common difference d=2. 

Therefore, Sn=n/2[2a+(n−1)d]

Sn=n/2[2×1+(n−1)×2]

Sn=n/2[2+2n−2]

Sn=n^2