Hello, The function in question has the following properties: 1. Is monotonically increasing 2. Is concave downwards 3. f(0) =0 I was trying to find a relation between sum(f(x_i)) and f(sum(x_i)) i=1 to i=n and all x_i positive. I tried a few things, including this: nx>=x f'(nx)<=f'(x) integrating 0 to x (1/n)f(nx)<=f(x) taking sigma sum((1/n)f(nx))<=sum(f(x)) i tried using this along with jensen's inequality but couldnt draw any conclusions. Any help would be greatly appreciated.