Question

The sum of 1+3+5+....... upto n terms is equal to​

Answer 1

Answer:

l don't know meaning of n

but l I think 9

Answer 2

Answer:

$n^{2}$

Step-by-step explanation:

METHOD 1:

Formula for summation of first 'n' odd numbers is '$n^{2}$'

METHOD 2:

The above series is a AP with first term(a)=1 and common difference(d)=2.

The formula for summation if the series is in AP is:

$S_{n}$=$\frac{n}{2} (2a+(n-1)d)$

Inserting the values in the above equation we get:

$S_{n} =\frac{n}{2}(2+(n-1)2)$

$S_{n} =\frac{n}{2} (2n)$

$S_{n} =n^{2}$