Let$ (X,M,\mu )$ is a measure space and $f,g$ are real valued functions on X .
Prove or disprove : if $f×g$ be measurable and $g(x) \neq 0 $ then $ \frac{f}{g} $ is measurable.
Let$ (X,M,\mu )$ is a measure space and $f,g$ are real valued functions on X .
Prove or disprove : if $f×g$ be measurable and $g(x) \neq 0 $ then $ \frac{f}{g} $ is measurable.
Copyright © 2021 JogjaFile Inc.
Let $E$ be a non-measurable set, and put $$f=2\times1_E+1_{E^c},\ \ \ \ \ \ \ \ g=\frac12\times1_E+1_{E^c}.$$ Then $$ f\times g = 1, $$ measurable. But $$ \frac fg=4\times1_E+1_{E^c}, $$ not measurable.