If the function is defined as \(f(x) = \begin{cases} x & x \in [0,1] \cap Q \\ 1-x & x \in [0,1] \cap Q^c \\ \end{cases}\) then
1
f(x) is Riemann Integrable on [0,1]
2
f(x) is not Riemann Integrable on [0,1]
3
f(x) is continuous at more than one points
4
f(x) is continuous at exactly two points