# Question: If f A R is integrable

If f: A →R is integrable, show that |f| is integrable and |f A f|

## Answer to relevant Questions

Let f: [0, 1] x [0, 1] → R be defined byLet f: [a, b] be an increasing function. Show that {x: f is discontinuous at x} is a set of measure 0.Let U be the open set of Problem 3-11. Show that if f = X except on a set of measure 0, then f is not integrable on [0, 1]Use Fubini's Theorem to give an easy proof that D1, 2f = D2, 1f if these are continuous.Use Theorem 3-14 to prove Theorem 3-13 without the assumption that g1 (x) ≠ 0.Post your question