meili 发表于 2022-10-27 15:29:31

若f(x)有二阶导数,且f(0)=f(1)=0,lim(x→0)[f(x)/x]=0,则在(0,1)内至少存在一点ξ,使fquot;(ξ)=0

<p>问题:若f(x)有二阶导数,且f(0)=f(1)=0,lim(x→0)=0,则在(0,1)内至少存在一点ξ,使fquot;(ξ)=0
<p>答案:↓↓↓<p class="nav-title mt10" style="border-top:1px solid #ccc;padding-top: 10px;">唐降龙的回答:<div class="content-b">网友采纳  f(x)有二阶导数,则f(x)一阶导数及f(x)连续可导f(x)/x→0(x→0)则f(x)→0(x→0)而f(x)连续,则(x→0)时,f(x)→0=f(0)=0则f(x)/x→0(x→0)=[(f(x)-f(0))/(x-0)]→0(x→0)即f'(0)=0因为f(0)=f(1)=0,根据罗...
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查看完整版本: 若f(x)有二阶导数,且f(0)=f(1)=0,lim(x→0)[f(x)/x]=0,则在(0,1)内至少存在一点ξ,使fquot;(ξ)=0