Suppose f(x) is a continuous function on [0, 1] such that
\(\int_0^1 f(x) \, dx = 0 \)
Which of the following must be true?
1
f(x) is identically zero on [0, 1].
2
f(x) is non-negative on [0, 1].
3
f(x) must change sign on [0, 1].
4
None of the above.