File r37/lisp/csl/html/r37_0156.html artifact e1c3d47461 part of check-in 3af273af29

<A NAME=LCOF>

<TITLE>LCOF</TITLE></A>
<b><a href=r37_idx.html>INDEX</a></b><p><p>



<B>LCOF</B> _ _ _  _ _ _  _ _ _  _ _ _ <B>operator</B><P>
<P>
 
 <P>
<P>
The <em>lcof</em> operator returns the leading coefficient of a given expression
 
with respect to a given variable. 
 <P> <H3> 
syntax: </H3>
<P>
<P>
<em>lcof</em>(&lt;expression&gt;,&lt;kernel&gt;) 
<P>
<P>
<P>
&lt;expression&gt; is ordinarily a polynomial. If 
<A HREF=r37_0322.html>ratarg</A> is on, 
a rational expression may also be used, otherwise an error results. 
&lt;kernel&gt; must be a 
<A HREF=r37_0002.html>kernel</A>. 
<P>
<P>
 <P> <H3> 
examples: </H3>
<P><PRE><TT>
lcof((x+2*y)**5,y); 

  32 


lcof((x + y*sin(x))**2 + cos(x)*sin(x)**2,sin(x));
			 


        2
  COS(X)  + Y 


lcof(x**2 + 3*x + 17,y); 

   2
  X  + 3*X + 17

</TT></PRE><P>If the kernel does not appear in the expression, <em>lcof</em> ret
urns the 
expression. 
<P>
<P>
<P>