meili 发表于 2022-10-27 15:17:33

设f(x)在x=0的某邻域内二阶连续可导,且f′(0)=0,limx→0xf″(x)1−cosx=1,则()A.f″(0)≠0,但(0,f(0))为y=f(x)的拐点B.f″(0)=0,且f(0)为f(x)的极小值C.f″(0)

<p>问题:设f(x)在x=0的某邻域内二阶连续可导,且f′(0)=0,limx→0xf″(x)1−cosx=1,则()A.f″(0)≠0,但(0,f(0))为y=f(x)的拐点B.f″(0)=0,且f(0)为f(x)的极小值C.f″(0)
<p>答案:↓↓↓<p class="nav-title mt10" style="border-top:1px solid #ccc;padding-top: 10px;">何立涛的回答:<div class="content-b">网友采纳  因为limx→0xf″(x)1−cosx=1≠0
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查看完整版本: 设f(x)在x=0的某邻域内二阶连续可导,且f′(0)=0,limx→0xf″(x)1−cosx=1,则()A.f″(0)≠0,但(0,f(0))为y=f(x)的拐点B.f″(0)=0,且f(0)为f(x)的极小值C.f″(0)