Question

if you was a corporator what will you do to reduse this pandemic disease in you are area​

Answer 1

it can be observed that every nth term is 2n more than the previous term so,

f(n+1)-f(n)=2n, given that f(1)=1

f(1)=1

f(2)=2*1+f(1)=2+1=3

....and so on.

Another observation is the difference of the differences is constant for these type of series is constant.

f(n+1)-f(n)=2n ..1

f(n)-f(n-1)=2(n-1) ..2

the difference between the equations is 2, which independent of n.