第一节 mathematica快速入门.htm

Mathematica软件包的介绍

style="FONT-FAMILY: 宋体">-3^2*((4/7+2)*5-8)^0.25<SPAN                 
style="mso-spacerun: yes">&nbsp; </SPAN>（*仅仅是把1/4改为0.25就会有不同的输出结果*）</SPAN><SPAN                   
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style="text-indent: 17.95pt; line-height: 200%"><SPAN lang=EN-US><b><font size="4" face="楷体_GB2312">Out[2]=-13.361<O:P> </O:P></font></b></SPAN></P>                  
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style="text-indent: 17.95pt; line-height: 200%"><b><SPAN lang=EN-US><font size="4" face="楷体_GB2312">In[3]:=-3^2*((4./7+2)*5-8)^(1/4)</font></SPAN><font size="4" face="楷体_GB2312"><SPAN lang=EN-US                 
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'"><O:P>                 
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style="text-indent: 17.95pt; line-height: 200%"><b><SPAN lang=EN-US><font size="4" face="楷体_GB2312">Out[3]=-13.361</font></SPAN><font size="4" face="楷体_GB2312"><SPAN lang=EN-US                 
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'"><O:P>                 
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style="text-indent: 17.95pt; line-height: 200%"><SPAN lang=EN-US                  
style="mso-hansi-font-family: Times New Roman"><b><font size="4" face="楷体_GB2312">&nbsp;<O:P>                 
</O:P></font></b></SPAN></P>                  
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style="mso-font-kerning: 0pt"><font size="4" face="楷体_GB2312" color="#FF0000">注意：                   
如果表达式中含有小数，则会输出近似值，否则输出准确值。“（<SPAN                  
lang=EN-US>*”和“*）” 之间为注释内容，不参加运算。</SPAN></font></SPAN><font size="4" face="楷体_GB2312"><SPAN lang=EN-US                 
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'; mso-font-kerning: 0pt"><O:P>                
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<P align=left class=MsoNormal style="line-height: 200%"><b><SPAN                 
style="mso-font-kerning: 0pt"><font size="4" face="楷体_GB2312">例<SPAN lang=EN-US>2                   
</SPAN></font></SPAN><SPAN                  
style="mso-hansi-font-family: Times New Roman; mso-font-kerning: 0pt"><font size="4" face="楷体_GB2312">求解表达式<SPAN                
lang=EN-US><SPAN style="mso-text-raise: -12.0pt"><!--[if gte vml 1]><V:SHAPE                
id=_x0000_i1028 style="HEIGHT: 33.75pt; WIDTH: 77.25pt" type="#_x0000_t75"                
o:ole=""> <V:IMAGEDATA o:title=""                
src="file:///C:/WINDOWS/TEMP/msoclip1/01/clip_image007.wmz"></V:SHAPE><![endif]--><IMG src="images/1.htm4.gif"                
v:shapes="_x0000_i1028" width="103" height="45"></SPAN></SPAN></font></SPAN></b></P>                
<P align=left class=MsoNormal style="line-height: 200%"><b><font size="4" face="楷体_GB2312"><SPAN                
lang=EN-US>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </SPAN></font><SPAN lang=EN-US><font size="4" face="楷体_GB2312">In[4]:=17^(1/3)*5*Pi+(4/9)^0</font></SPAN><B                 
style="mso-bidi-font-weight: normal"><font size="4" face="楷体_GB2312"><SPAN lang=EN-US                
style="FONT-SIZE: 12pt; mso-bidi-font-size: 10.0pt"><O:P> </O:P></SPAN></font></B></b></P>                
<P class=MsoNormal style="text-indent: 17.95pt; line-height: 200%"><b><SPAN lang=EN-US><font size="4" face="楷体_GB2312">Out[4]=<SPAN style="mso-text-raise: -12.0pt"><!--[if gte vml 1]><V:SHAPE id=_x0000_i1029                
style="HEIGHT: 33pt; WIDTH: 53.25pt" type="#_x0000_t75" o:ole=""> <V:IMAGEDATA                
o:title=""                
src="file:///C:/WINDOWS/TEMP/msoclip1/01/clip_image009.wmz"></V:SHAPE><![endif]--></SPAN><!--[if gte mso 9]><xml>               
 <o:OLEObject Type="Embed" ProgID="Equation.3" ShapeID="_x0000_i1029"               
  DrawAspect="Content" ObjectID="_1048958859">               
 </o:OLEObject>               
</xml><![endif]-->                
 <img SRC="IMAGES/Image4.gif" width="102" height="20"></font></SPAN><font size="4" face="楷体_GB2312"><SPAN lang=EN-US                
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'"><O:P></O:P></SPAN></font></b></P>               
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style="text-indent: 17.95pt; line-height: 200%"><SPAN lang=EN-US><b><font size="4" face="楷体_GB2312">In[5]:=N[17^(1/3)*5*Pi+(4/9)^0,20]<O:P>                
</O:P></font></b></SPAN></P>                
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style="text-indent: 17.95pt; line-height: 200%"><b><SPAN lang=EN-US><font size="4" face="楷体_GB2312">Out[5]=41.389596777612950615</font></SPAN><font size="4" face="楷体_GB2312"><SPAN lang=EN-US                
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'"><O:P>                
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style="text-indent: 17.95pt; line-height: 200%"><b><font size="4" face="楷体_GB2312">比较：<SPAN lang=EN-US                
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'"><O:P>                
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style="text-indent: 17.95pt; line-height: 200%"><SPAN lang=EN-US><b><font size="4" face="楷体_GB2312">In[6]:=N[17^(1/3)*5.0*Pi+(4/9)^0,20]<O:P>                
</O:P></font></b></SPAN></P>                  
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style="text-indent: 17.95pt; line-height: 200%"><b><SPAN lang=EN-US><font size="4" face="楷体_GB2312">Out[6]=41.3896</font></SPAN><font size="4" face="楷体_GB2312"><SPAN lang=EN-US                 
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'"><O:P>                 
</O:P></SPAN></font></b></P>                 
<P align=left class=MsoNormal style="line-height: 200%"><b><font size="4" face="楷体_GB2312">例<SPAN lang=EN-US>3 </SPAN><SPAN                   
style="mso-hansi-font-family: Times New Roman; mso-font-kerning: 0pt">求表达式<SPAN                  
lang=EN-US><SPAN style="mso-text-raise: -4.0pt"><!--[if gte vml 1]><V:SHAPE                  
id=_x0000_i1030 style="HEIGHT: 18pt; WIDTH: 35.25pt" type="#_x0000_t75"                  
o:ole=""> <V:IMAGEDATA o:title=""                  
src="file:///C:/WINDOWS/TEMP/msoclip1/01/clip_image011.wmz"></V:SHAPE><![endif]--><IMG src="images/1.htm6.gif"                  
v:shapes="_x0000_i1030" width="47" height="24"></SPAN><!--[if gte mso 9]><xml>                 
 <o:OLEObject Type="Embed" ProgID="Equation.3" ShapeID="_x0000_i1030"                 
  DrawAspect="Content" ObjectID="_1048958860">                 
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<O:P></O:P></SPAN></SPAN></font></b></P>                 
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style="text-indent: 17.95pt; line-height: 200%"><SPAN lang=EN-US><b><font size="4" face="楷体_GB2312">In[7]:=Sqrt[Sin[2.]]<O:P> </O:P></font></b></SPAN></P>                  
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style="text-indent: 17.95pt; line-height: 200%"><b><SPAN lang=EN-US><font size="4" face="楷体_GB2312">Out[7]=0.953571</font></SPAN><font size="4" face="楷体_GB2312"><SPAN lang=EN-US                 
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'"><O:P>                 
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<P class=MsoNormal style="line-height: 200%"><b><font face="楷体_GB2312"><span style="mso-hansi-font-family: Times New Roman; mso-ascii-font-family: Times New Roman"><font size="5" color="#FF0000">二、<a name="变量与赋值">变量与赋值</a><O:P>              
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 </span><font size="4"><SPAN lang=EN-US              
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</O:P></SPAN></font></font></b></P>             
<P align=left class=MsoNormal              
style="text-indent: 17.95pt; punctuation-wrap: simple; mso-line-break-override: restrictions; line-height: 200%"><b><font size="4" face="楷体_GB2312">在<SPAN              
lang=EN-US>Mathematica中可以用一些字母表示一个数学函数，比如Sin[2]。也可以用一些字母表示某个具体的数字,比如Pi=3.1415……，在一些计算中往往需要保留大量的中间结果，我们就用一些字母表示这些数字。</SPAN><SPAN              
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style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'"><O:P>              
</O:P></SPAN></font></b></P>              
<P align=left class=MsoNormal               
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lang=EN-US><font size="4" face="楷体_GB2312"><font color="#FF0000">1．变量</font></font></SPAN><font size="4" face="楷体_GB2312"><SPAN lang=EN-US             
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'"><font color="#FF0000"><O:P>             
 </font>             
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lang=EN-US><SPAN style="mso-spacerun: yes"><font size="4" face="楷体_GB2312">&nbsp;&nbsp;       
</font>                
</SPAN><font size="4" face="楷体_GB2312">在程序执行过程中，其值不断变化的量称为变量。其标示符应该由字母开头的字母数字串组成，可以包含任意多的字母数字，但不能包含空格和标点符号，比如mn，h2，Math4，ToPo都是合法变量名。在Mathematica中，变量不仅可以表示一个数字，也可表示一个表达式，比如多项式或复杂的算式，甚至一个图片。</font></SPAN><font size="4" face="楷体_GB2312"><SPAN                
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style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'"><O:P>                
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lang=EN-US><font size="4" face="楷体_GB2312"><font color="#FF0000">2．变量的赋值</font></font></SPAN><font size="4" face="楷体_GB2312"><SPAN lang=EN-US               
style="FONT-FAMILY: 宋体; mso-hansi-font-family: 'Times New Roman'"><font color="#FF0000"><O:P>               
 </font>               
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