RATIONALIZE _ _ _ _ _ _ _ _ _ _ _ _ switch

When the rationalize switch is on, denominators of rational expressions that contain complex numbers or root expressions are simplified by multiplication by their conjugates.

examples:

qq := (1+sqrt(3))/(sqrt(3)-7); 

        SQRT(3) + 1
  QQ := ----------- 
        SQRT(3) - 7


on rationalize; 

qq; 

  - 4*SQRT(3) - 5
  --------------- 
        23


2/(4 + 6**(1/3)); 

   2/3      1/3
  6    - 4*6    + 16
  ------------------ 
          35


(i-1)/(i+3); 

  2*I - 1
  ------- 
     5


off rationalize; 

(i-1)/(i+3); 

  I - 1
  ------
  I + 3