ERF INDEX

ERF _ _ _ _ _ _ _ _ _ _ _ _ operator

The erf operator represents the error function, defined by

erf(x) = (2/sqrt(pi))*int(e^(-x^2),x)

A limited number of its properties are known to the system, including the fact that it is an odd function. Its derivative is known, and from this, some integrals may be computed. However, a complete integration procedure for this operator is not currently included.

examples:


erf(0); 

  0 


erf(-a); 

  - ERF(A) 


df(erf(x**2),x); 

  4*SQRT(PI)*X
  ------------ 
       4
      X
     E  *PI



int(erf(x),x); 

    2
   X
  E  *ERF(X)*PI*X + SQRT(PI)
  ---------------------------
              2
             X
            E  *PI