Prove that $f(x)=x$ is not Lebesgue integrable on $[1, \infty)$. (hint: use def. of Lebesgue integrability for positive functions).
hint: Use integral $= \infty$ by defining simple function and $\chi_A$ characteristic function.
Prove that $f(x)=x$ is not Lebesgue integrable on $[1, \infty)$. (hint: use def. of Lebesgue integrability for positive functions).
hint: Use integral $= \infty$ by defining simple function and $\chi_A$ characteristic function.