Suppose that f: [a,b] \rightarrow \mathbb{R} is continuous and f(x) \geq 0 for all x \in [a,b]. Prove that if \int^b_a f(x)dx=0, then f(x)=0 for all x \in [a,b].
Attempt
I had attempted to do this problem by contradiction, except I did not understand how to finish the problem. I would...