Question

2. (i) Find the mean of first n natural numbers.​

Answer 1

Answer:

n(n+1)/2

I hope u will get it.......

Answer 2

Answer:

a(first term) = 1

d(common difference) = 1

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

= n/2 [2+n-1]

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

= (n^2 + n) / 2

OR

Sn = n/2 (t1 + tn)

= n/2 (1 + n)

= (n + n^2) / 2

= (n^2 + n) / 2