Here's the question you clicked on:
swin2013
Use the max-min inequality to show that if f is integrable then f(x) ≤ 0 on [a,b] -> ∫ (from a to be) f(x) d(X) ≥ 0
of \(f(x)\) is never positive, then neither is the integral
are you saying there is no way of showing it? or the question does not have a definite answer?