NAME    [Toc]    [Back]

     atan, atanf -- arc tangent functions of one variable

LIBRARY    [Toc]    [Back]

     Math Library (libm, -lm)

SYNOPSIS    [Toc]    [Back]

     #include <math.h>

     double
     atan(double x);

     float
     atanf(float x);

DESCRIPTION    [Toc]    [Back]

     The atan() and the atanf() functions compute the principal value of the
     arc tangent of x.	For a discussion of error due to roundoff, see
     math(3).

RETURN VALUES    [Toc]    [Back]

     The atan() and the atanf() function returns the arc tangent in the range
     [-pi/2, +pi/2] radians.

SEE ALSO    [Toc]    [Back]

     acos(3), asin(3), atan2(3), cos(3), cosh(3), math(3), sin(3), sinh(3),
     tan(3), tanh(3)

STANDARDS    [Toc]    [Back]

     The atan() function conforms to ISO/IEC 9899:1990 (``ISO C89'').


FreeBSD 5.2.1			  May 2, 1991			 FreeBSD 5.2.1