DEN INDEX

DEN _ _ _ _ _ _ _ _ _ _ _ _ operator

The den operator returns the denominator of its argument.

syntax:

den(<expression>)

<expression> is ordinarily a rational expression, but may be any valid scalar REDUCE expression.

examples:



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

denreturns 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.

Switch settings, such as mcd or rational, have an effect on the denominator of an expression.