Question

find the sum of first n natural number ​

Answer 1

Step-by-step explanation:

formula is =n (n+1)/2 so solve it ok

Answer 2

Step-by-step explanation:

natural no. = 1,2,3,4.....

sum of first n natural no. = n/2{2a +(n-1)d} ,by AP

= n/2 {2(1) + (n-1)×1 }

= n/2 (2 +n-1)

= n/2(n+1)