Calculates the inverse tangent of a number #include <math.h> double atan ( double x ); float atanf ( float x ); (C99) long double atanl ( long double x ); (C99) atan( ) implements the inverse tangent function, commonly called arc tangent. The return value is given in radians, and is thus in the range -p/2 atan(x) atanl( 1.0L ); // Because tan(pi/4) = 1 #endif printf( "Assume pi equals %.17Lf.\n", pi); This code produces the following output: The arc tangent functions for complex numbers: catan( ), catanf( ), and catanl( ) |