高等数学设函数f(x)在点x0处有连续的二阶导数,证明lim(h→0)[f(x0+h)+f(x0-h)-2f(x0)]/hamp;#178;=f#39;#39;(x0).
<p>问题:高等数学设函数f(x)在点x0处有连续的二阶导数,证明lim(h→0)[f(x0+h)+f(x0-h)-2f(x0)]/hamp;#178;=f#39;#39;(x0).<p>答案:↓↓↓<p class="nav-title mt10" style="border-top:1px solid #ccc;padding-top: 10px;">黄文恺的回答:<div class="content-b">网友采纳 原式=lim(h→0)[f(x0+h)-f'(x0-h)-2f(x0)]/h² =1/2lim(h→0)[f'(x0+h)+f'(x0-h)-2f'(x0)]/h =1/2lim(h→0)[f'(x0+h)-f'(x0)]+1/2lim(h→0)[f'(x0-h)]/(-h) =1/2f''(x0)+1/2f''(x0) =f''(x0)
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