Discussion:
Q: Every rational x can be written in the form x = m/n, where n > 0, and m and n are integers without any common divisors. When x = 0, we take n = 1. Consider the function f defined on the reals where f(x) = 0 when x is irrational and f(x)= 1/n when x =m/n
a, prove that f(x) is continuous at every irrational point and discontinuous at every rational point
b, show that f is integrable on [0,1]