ATAN _ _ _ _ _ _ _ _ _ _ _ _ operator

The atan operator returns the arctangent of its argument.

syntax:

<expression> may be any scalar REDUCE expression, not an array, matrix or vector expression. <simple\_expression> must be a single identifier or begin with a prefix operator name.

examples:

atan(middle); 

  ATAN(MIDDLE) 


on rounded; 

atan 45; 

  1.54857776147 


off rounded; 

int(atan(x),x); 

                     2
  2*ATAN(X)*X - LOG(X  + 1)
  ------------------------- 
              2


df(atan(y**2),y); 

   2*Y
  -------
   4
  Y  + 1

A numeric value is not returned by atan unless the switch rounded is on and its argument evaluates to a number.