Functie integrabila, convexa si cu integrala nula => f=0

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Cezar Lupu
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Functie integrabila, convexa si cu integrala nula => f=0

Post by Cezar Lupu »

Fie \( f:[0,1]\to [0, \infty) \) o functie integrabila si convexa astfel incat

\( \int_0^1f(x)dx=0 \).

Sa se arate ca \( f(x)=0,\forall x\in (0,1) \).
An infinite number of mathematicians walk into a bar. The first one orders a beer. The second orders half a beer. The third, a quarter of a beer. The bartender says “You’re all idiots”, and pours two beers.
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Alin Galatan
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Post by Alin Galatan »

Presupunem ca exista un punct a din \( (0,1) \) unde \( f(a)>0 \). Fiind convexa, pe o vecinatate a lui a este continua, deci este strict pozitiva pe o vecintate, ceea ce contrazice ipoteza.
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