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Is there any difference between a function being integrable (since there are many ways to define whether a function is integrable, let's stick to Riemann integration.) and it's antiderivative existing? The antiderivative need not be any simple/analytic function.

vonbrand
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2 Answers2

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Yes. For instance, the function $f(0) = 1$, $f(x) = 0$ for $x \ne 0$ is integrable in any interval, but has no antiderivative.

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Adding to the discussion, if a function has an antiderivative, is it integrable? This depends on how you define the integration

http://en.wikipedia.org/wiki/Volterras_function

This function is not Riemannian integrable even though it is bounded and antiderivative exists everywhere. I wonder, does existence of an antiderivative imply Lebesgue integrability?

Pedro
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muzzlator
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