<HTML> <HEAD> <!-- This HTML file has been created by texi2html 1.52 from maxima.texi on 25 April 2001 --> <TITLE>Maxima Manual - Limits</TITLE> <link href="maxima_18.html" rel=Next> <link href="maxima_16.html" rel=Previous> <link href="maxima_toc.html" rel=ToC> </HEAD> <BODY> <p>Go to the <A HREF="maxima_1.html">first</A>, <A HREF="maxima_16.html">previous</A>, <A HREF="maxima_18.html">next</A>, <A HREF="maxima_41.html">last</A> section, <A HREF="maxima_toc.html">table of contents</A>. <P><HR><P> <H1><A NAME="SEC56" HREF="maxima_toc.html#TOC56">Limits</A></H1> <H2><A NAME="SEC57" HREF="maxima_toc.html#TOC57">Definitions for Limits</A></H2> <P> <DL> <DT><U>Variable:</U> <B>LHOSPITALLIM</B> <DD><A NAME="IDX462"></A> default: [4] - the maximum number of times L'Hospital's rule is used in LIMIT. This prevents infinite looping in cases like LIMIT(COT(X)/CSC(X),X,0). </P> </DL> <P> <DL> <DT><U>Function:</U> <B>LIMIT</B> <I>(exp, var, val, dir)</I> <DD><A NAME="IDX463"></A>finds the limit of exp as the real variable var approaches the value val from the direction dir. Dir may have the value PLUS for a limit from above, MINUS for a limit from below, or may be omitted (implying a two-sided limit is to be computed). For the method see Wang, P., "Evaluation of Definite Integrals by Symbolic Manipulation" - Ph.D. Thesis - MAC TR-92 October 1971. LIMIT uses the following special symbols: INF (positive infinity) and MINF (negative infinity). On output it may also use UND (undefined), IND (indefinite but bounded) and INFINITY (complex infinity). LHOSPITALLIM[4] is the maximum number of times L'Hospital's rule is used in LIMIT. This prevents infinite looping in cases like LIMIT(COT(X)/CSC(X),X,0). TLIMSWITCH[FALSE] when true will cause the limit package to use Taylor series when possible. LIMSUBST[FALSE] prevents LIMIT from attempting substitutions on unknown forms. This is to avoid bugs like LIMIT(F(N)/F(N+1),N,INF); giving 1. Setting LIMSUBST to TRUE will allow such substitutions. Since LIMIT is often called upon to simplify constant expressions, for example, INF-1, LIMIT may be used in such cases with only one argument, e.g. LIMIT(INF-1); Do EXAMPLE(LIMIT); for examples. </P> </DL> <P> <DL> <DT><U>Function:</U> <B>TLIMIT</B> <I>(exp,var,val,dir)</I> <DD><A NAME="IDX464"></A>is just the function LIMIT with TLIMSWITCH set to TRUE. </P> </DL> <P> <DL> <DT><U>Variable:</U> <B>TLIMSWITCH</B> <DD><A NAME="IDX465"></A> default: [FALSE] - if true will cause the limit package to use Taylor series when possible. </P> </DL> <P><HR><P> <p>Go to the <A HREF="maxima_1.html">first</A>, <A HREF="maxima_16.html">previous</A>, <A HREF="maxima_18.html">next</A>, <A HREF="maxima_41.html">last</A> section, <A HREF="maxima_toc.html">table of contents</A>. </BODY> </HTML>