ch11_1_2.htm
来自「一个不错的matlab工程实际问题的解决方法」· HTM 代码 · 共 87 行
HTM
87 行
<! Made by Html Translation Ver 1.0>
<HTML>
<HEAD>
<TITLE> 数学式的化简 </TITLE>
</HEAD>
<BODY BACKGROUND="bg0000.gif" tppabs="http://166.111.167.223/computer/cai/matlabjc/img/bg0000.gif">
<FONT COLOR="#0000FF">
<H1>11.1.2 数学式的化简</H1>
</FONT>
<HR>
<P>
以下的函数适用来简化数学式，如展开、化简或聚集数学式。相关的指令有：
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">collect(S)</FONT>
聚集<FONT COLOR=#FF0000 FACE="Times New Roman">S</FONT>的系数
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">collect(S,</FONT><FONT COLOR=#FF0000>'</FONT><FONT COLOR=#FF0000 FACE="Times New Roman">v</FONT><FONT COLOR=#FF0000>'</FONT><FONT COLOR=#FF0000 FACE="Times New Roman">)</FONT>
聚集<FONT COLOR=#FF0000 FACE="Times New Roman">S</FONT>的系数，是以<FONT COLOR=#FF0000 FACE="Times New Roman">v</FONT>为独立变数
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">expand(S) </FONT> 将<FONT COLOR=#FF0000 FACE="Times New Roman">S</FONT>表示式展开
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">factor(S)</FONT>
还原<FONT COLOR=#FF0000 FACE="Times New Roman">S</FONT>的因式<FONT FACE="Times New Roman">(factorization)</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">simple(S)</FONT>
如果可能的话，将<FONT COLOR=#FF0000 FACE="Times New Roman">S</FONT>表示式再做简化
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">simplify(S)</FONT>
利用<FONT FACE="Times New Roman">Maple</FONT>简化法则化简<FONT COLOR=#FF0000 FACE="Times New Roman">S</FONT>表示式
<BR>
<P>
我们来看一些例子
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">>> S1 = </FONT><FONT COLOR=#FF0000>'</FONT><FONT COLOR=#FF0000 FACE="Times New Roman">x^3-1</FONT><FONT COLOR=#FF0000>'</FONT><FONT COLOR=#FF0000 FACE="Times New Roman">;</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">>> S2 = </FONT><FONT COLOR=#FF0000>'</FONT><FONT COLOR=#FF0000 FACE="Times New Roman">(x-3)^2+(y-4)^2</FONT><FONT COLOR=#FF0000>'</FONT><FONT COLOR=#FF0000 FACE="Times New Roman">;</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">>> S3 = </FONT><FONT COLOR=#FF0000>'</FONT><FONT COLOR=#FF0000 FACE="Times New Roman">sqrt(a^4*b^7)</FONT><FONT COLOR=#FF0000>'</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">>> S4 = </FONT><FONT COLOR=#FF0000>'</FONT><FONT COLOR=#FF0000 FACE="Times New Roman">14*x^2/(22*x*y)</FONT><FONT COLOR=#FF0000>'</FONT><FONT COLOR=#FF0000 FACE="Times New Roman">;
<BR>
</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">>> factor(S1)</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">ans=</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">(x-1)*(x^2+x+1)</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">>> expand(S2)</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">ans=</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">x^2-6*x+25+y^2-8*y</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">>>collect(S2)</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">ans=</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">x^2-6*x+9+(y-4)^2</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">>>collect(S2,</FONT><FONT COLOR=#FF0000>'</FONT><FONT COLOR=#FF0000 FACE="Times New Roman">y</FONT><FONT COLOR=#FF0000>'</FONT><FONT COLOR=#FF0000 FACE="Times New Roman">)</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">ans=</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">y^2-8*y+(x-3)62+16</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">>>simplify(S3)</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">ans=</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">a^2*b^(7/2)</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">>>simple(S4)</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">ans=</FONT>
<P>
<FONT COLOR=#FF0000 FACE="Times New Roman">7/11*x/y</FONT><HR>
<A HREF="ch11_1_1.htm" tppabs="http://166.111.167.223/computer/cai/matlabjc/ch11_1_1.htm"><IMG SRC="lastpage.gif" tppabs="http://166.111.167.223/computer/cai/matlabjc/img/lastpage.gif" BORDER=0></A>
<A HREF="ch11_1_3.htm" tppabs="http://166.111.167.223/computer/cai/matlabjc/ch11_1_3.htm"><IMG SRC="nextpage-1.gif" tppabs="http://166.111.167.223/computer/cai/matlabjc/img/nextpage.gif" BORDER=0 HSPACE=10></A>
<A HREF="index.html" tppabs="http://166.111.167.223/computer/cai/matlabjc/index.html"><IMG SRC="outline-1.gif" tppabs="http://166.111.167.223/computer/cai/matlabjc/img/outline.gif" BORDER=0 HSPACE=6></A><BR>
<FONT SIZE=2 COLOR=#AA55FF> 上一页 下一页 讲义大纲 </FONT>
</BODY>
</HTML>
⌨️ 快捷键说明
复制代码Ctrl + C
搜索代码Ctrl + F
全屏模式F11
增大字号Ctrl + =
减小字号Ctrl + -
显示快捷键?