Question

the sum of the first n natural number is given by n(n+1)/2​

Answer 1

Answer:

proof

Step-by-step explanation:

have a glance hope it helps, if any ERROR please comment

Answer 2

Answer:

yes

sn =n(n-1)/2

$let \: the \: a = 1 \: \: n = n \: \: an = n$

then

$sn = \frac{n(a + an)}{2}$

sn=(n+1)/2