Measure, Integration & Real Analysis · Problem 6B.6
Banach Spaces — Sheldon Axler
Mathematics — Measure Theory · measurability-algebraic-combinations-complex
Problem
Suppose (X,S) is a measurable space and f,g:X→C are S-measurable. Prove that
(a) f+g, f−g, and fg are S-measurable functions;
(b) if g(x)=0 for all x∈X, then gf is an S-measurable function.