Let \(f\) be an increasing function on \([a,b]\subset\mathbb R\). Use
the fact that there is a Borel measure \(\mu\) on \([a,b]\) such that
\(\mu([a,x])=f(x)-f(a)\) for all \(a\le x\le b\) to prove that
\[
\int_a^b f'\,dm\le f(b)-f(a),
\]
where \(m\) denotes Lebesgue measure on \([a,b]\).
Question
Math 6210 • Real Analysis
Fall 1995 • Question 5