Let \((\mathcal M,\mu ,X)\) be a positive measure space. Let \(\mathcal M'\) denote the collection of subsets (in \(\mathcal M\)) whose measures are finite. Prove that \[ L^2(X)\subset L^1(X) \] if and only if \[ \sup _{E\in \mathcal M'}\mu (E)<\infty . \]
Question
Math 6210 • Real Analysis
2005 • Question 2