atan [function]
atan( x )
returns the arctangent of x (angle in radians), as real
atan( 0 ); // real (0) atan( 1 ); // real (0.785398) atan( 9999999 ); // real (1.5708)
x (angle in radians), as realatan( 0 ); // real (0) atan( 1 ); // real (0.785398) atan( 9999999 ); // real (1.5708)