β ( x , a , b ) = ∫ 0 x  t a − 1      ( 1 − t )  b − 1   d t       ( 71 )   MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaaiiGacqWFYoGycqGGOaakcqWG4baEcqGGSaalcqWGHbqycqGGSaalcqWGIbGycqGGPaqkcqGH9aqpdaWdXaqaaiabdsha0naaCaaaleqabaGaemyyaeMaeyOeI0IaeGymaedaaaqaaiabicdaWaqaaiabdIha4bqdcqGHRiI8aOGaeiikaGIaeGymaeJaeyOeI0IaemiDaqNaeiykaKYaaWbaaSqabeaacqWGIbGycqGHsislcqaIXaqmaaGccqWGKbazcqWG0baDcaWLjaGaaCzcaiabcIcaOiabiEda3iabigdaXiabcMcaPaaa@5037@