
<A NAME=DEN>

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



<B>DEN</B> _ _ _  _ _ _  _ _ _  _ _ _ <B>operator</B><P>
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The <em>den</em> operator returns the denominator of its argument. 
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syntax: </H3>
<em>den</em>(&lt;expression&gt;) 
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&lt;expression&gt; is ordinarily a rational expression, but may be any valid 
scalar REDUCE expression. 
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examples: </H3>
<P><PRE><TT>

a := x**3 + 3*x**2 + 12*x; 

           2
  A := X*(X   + 3*X + 12) 



b := 4*x*y + x*sin(x); 

  B := X*(SIN(X) + 4*Y) 



den(a/b); 

  SIN(X) + 4*Y 



den(aa/4 + bb/5); 

  20 



den(100/6); 

  3 



den(sin(x)); 

  1

</TT></PRE><P><em>den</em>returns the denominator of the expression after it has
 been 
simplified by REDUCE. As seen in the examples, this includes putting 
sums of rational expressions over a common denominator, and reducing 
common factors where possible. If the expression does not have any 
other denominator, 1 is returned. 
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Switch settings, such as 
<A HREF=r37_0304.html>mcd</A> or 
<A HREF=r37_0323.html>rational</A>, have an 
effect on the denominator of an expression. 
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