Does $\int_{-\infty}^{\infty}f(x)\,dx$ exist?

63 Views Asked by At

Let $f:\Bbb R\to \Bbb C$ be a continuous map, if $\int_{-\infty}^{\infty}|f(x)|\,dx$ exists, then $\int_{-\infty}^{\infty}f(x)\,dx$ exists, doesn't it?

1

There are 1 best solutions below

1
On

I am assuming that you are dealing with the Riemann integral here. Yes, that is correct, assuming that the restriction of $f$ to any interval $[a,b]$ is Riemann-integrable. That's a consequence of Cauchy's criterion.