1个德国中学的家庭作业
<br /="/"/><p>X*X = X+X+X.....+X <span style="display:none;">www.ddhw.com</span><br /="/"/><br /="/"/>(X*X)' = X'+ X'+X'.....+X' <span style="display:none;">www.ddhw.com</span><br /="/"/><br /="/"/>2X = 1+1+1......+1 <span style="display:none;">www.ddhw.com</span><br /="/"/><br /="/"/>2X = X <span style="display:none;">www.ddhw.com</span><br /="/"/><br /="/"/>2 = 1 <span style="display:none;">www.ddhw.com</span><br /="/"/><br /="/"/>错在哪儿<span style="display:none;">www.ddhw.com</span><br /="/"/><br /="/"/> <div style="MARGIN-TOP:20px;MARGIN-LEFT:0;MARGIN-BOTTOM:0;float:left"></div></p>回复：1个德国中学的家庭作业
<table cellpadding="8" height="100%" width="100%"><tr><td valign="top"><br /="/"/><div>the first line is wrong.</div><div>If it holds, the x must be a integer. The following derivative is not justified.</div><br /="/"/><br /="/"/> <div style="MARGIN-TOP:20px;MARGIN-LEFT:0;MARGIN-BOTTOM:0;float:left"></div></td></tr></table>回复：1个德国中学的家庭作业
<table cellpadding="8" height="100%" width="100%"><tr><td valign="top"><br /="/"/><div>To find the problem, see the following:</div><div>Let x =1.</div><div>Then x'=1',</div><div>that is, 1 = 0.</div><span style="display:none;">www.ddhw.com</span><br /="/"/><br /="/"/> <div style="MARGIN-TOP:20px;MARGIN-LEFT:0;MARGIN-BOTTOM:0;float:left"></div></td></tr></table>haha, a trying[:))][:))]
<table cellpadding="8" height="100%" width="100%"><tr><td valign="top"><br /="/"/>For a given equation 1, the number of term on the left side is GIVEN, as X (X= integer, can be 0 to infinity). So X here is a number, not a variable.<br /="/"/>Taking derivative of the both sides of equation 1 will yield<br /="/"/><br /="/"/>0 = 0+0+0.....+0<br /="/"/><br /="/"/>so <br /="/"/><br /="/"/>0 =0<br /="/"/><span style="display:none;">www.ddhw.com</span><br /="/"/><br /="/"/> <p><div align="right"><font color="#ff0000" style="BACKGROUND-COLOR: #c4dfff"> 本贴由[<b>salmonfish</b>]最后编辑于：2008-9-18 22:18:8 </font></div><div style="MARGIN-TOP:20px;MARGIN-LEFT:0;MARGIN-BOTTOM:0;float:left"></div></p></td></tr></table>回复：1个德国中学的家庭作业
<table cellpadding="8" height="100%" width="100%"><tr><td valign="top"><br /="/"/><div>只有在X不等于0的前提下，才可以在等式两端同时除以X；即使假定X不等于0，从第二步到第三步也不成立。第三个等式应该写成：</div><div>(X<>0) X=1+1+....+1</div><br /="/"/><br /="/"/> <div style="MARGIN-TOP:20px;MARGIN-LEFT:5px;MARGIN-BOTTOM:10px"><br /="/"/><img /="/" src="/img/sign.gif"></img><a href="http://www.ddhw.org" target="_top"><span style="FONT-SIZE:12px;COLOR:#999999;font-weight:bold">www.ddhw.org</span></a>---<div style="width:450px;MARGIN-LEFT:10px"><div></div><p><input /="/" src="http://upload.ddhw.cn/image/2008/05/28/9889.jpg" style="CURSOR: default" type="image"/></p><p>据说这世界是彩色的？<div> </div><div></div></p></div></div></td></tr></table>新新莫非在帮谁做作业？？[:-K][:-K]
<table cellpadding="8" height="100%" width="100%"><tr><td valign="top"><br /="/"/>答案呢？？？！！！！<img /="/" src="http://info.ddhw.com/img/8.gif"></img><div></div><span style="display:none;">www.ddhw.com</span><br /="/"/><br /="/"/> <div style="MARGIN-TOP:20px;MARGIN-LEFT:5px;MARGIN-BOTTOM:10px"><br /="/"/><img /="/" src="/img/sign.gif"></img><a href="http://www.ddhw.org" target="_top"><span style="FONT-SIZE:12px;COLOR:#999999;font-weight:bold">www.ddhw.org</span></a>---<div style="width:450px;MARGIN-LEFT:10px"><div></div><p><input /="/" src="http://upload.ddhw.cn/image/2008/05/28/9889.jpg" style="CURSOR: default" type="image"/></p><p>据说这世界是彩色的？<div> </div><div></div></p></div></div></td></tr></table>回复：1个德国中学的家庭作业
<table cellpadding="8" height="100%" width="100%"><tr><td valign="top"><br /="/"/><div></div><div><p>右边求导过程出错。因为 X+X+X.....+X 的项数依赖于X，函数和的求导公式不能用，即 (X+X+X+...+X)'<span style="FONT-FAMILY: Symbol; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'; mso-char-type: symbol; mso-symbol-font-family: Symbol"><span style="mso-char-type: symbol; mso-symbol-font-family: Symbol"><font size="3">¹</font></span></span>X'+X'+X'+...+X'。</p></div><span style="display:none;">www.ddhw.com</span><br /="/"/><br /="/"/> <div style="MARGIN-TOP:20px;MARGIN-LEFT:0;MARGIN-BOTTOM:0;float:left"></div></td></tr></table>
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