PRECISE _ _ _ _ _ _ _ _ _ _ _ _ switch

When the precise switch is on, simplification of roots of even powers returns absolute values, a more precise answer mathematically. Default is on.

examples:

sqrt(x**2); 

  X 


(x**2)**(1/4); 

  SQRT(X) 


on precise; 

sqrt(x**2); 

  ABS(X) 


(x**2)**(1/4); 

  SQRT(ABS(X))

In many types of mathematical work, simplification of powers and s urds can proceed by the fastest means of simplifying the exponents arithmetically. When it is important to you that the positive root be returned, turn precise on. One situation where this is important is when graphing square-root expressions such as sqrt(x^2+y^2) to avoid a spike caused by REDUCE simplifying sqrt(y^2) to y when x is zero.