Question

find the sum of first n natural numbers

Answer 1

see it as an arithmetic progression with first term 1 and total terms n with common difference 1 then apply the formula for the sum you'll get n(n+1)/2

Answer 2

Answer:

apply formula s↓n = n÷2 (a+l) here a=1 and last term is n

Step-by-step explanation:

s↓n = n÷2 (a+l)

=n÷2 (1+n)