Syntax

  #include <math.h>  
   
  double atan  (  
     double   x);
  

Parameters

x

(IN) Specifies an argument whose arc tangent is to be computed.

Return Values

The atan function returns the arc tangent in the range (-pi/2, pi/2).

See Also

acos, asin, atan2

Example

  #include <math.h>  
  #include <stdio.h>  
   
  main ()  
  {  
     printf ("%f\n", atan(.5) );  
  }
  

produces the following:

  0.463648