I have been trying to teach myself Lebesgue Integration and came across the following question in a textbook.
Let $g \subset [0,1]$ be bounded and measurable. Suppose that it satisifes the property $\int_{[0,1]} g \chi_{[0,c)}\, d\mu = 0$ for all $c \in [0,1]$. Show that $g=0$ a.e.