連續(xù)函數(shù)必有原函數(shù)不連續(xù)函數(shù)若有原函數(shù),則此原函數(shù)若有間斷點,則必為第2類間斷點跳躍性函數(shù)均無原函數(shù)請給出詳細的分析謝謝
熱心網(wǎng)友
1。連續(xù)函數(shù)必有原函數(shù)是顯然的,看一下定積分的內(nèi)容就清楚了,(對上限求導)。2。“不連續(xù)函數(shù)若有原函數(shù),則此原函數(shù)若有間斷點,則必為第2類間斷點”?命題應為:不連續(xù)函數(shù)f(x)若有原函數(shù)F(x),則f(x)若有間斷點,則必為第2類間斷點。F’(x)=f(x)。反證法,設(shè)F’(x)=f(x)在a有第1類間斷點。==》Lim{x→a-}f(x)=A,Lim{x→a+}f(x)=B,Lim{x→a-}[F(x)-F(a)]/[x-a]=F’(a)=f(a)==Lim{x→a-}F’(u)=,(x