ATAN(III) 4/30/73 ATAN(III) NAME atan - arc tangent function SYNOPSIS jsr r5,atan[2] double atan(x) double x; double atan2(x, y) double x, y; DESCRIPTION The atan entry returns the arc tangent of fr0 in fr0; from C, the arc tangent of x is returned. The range is -π/2 to π/2. The atan2 entry returns the arc tangent of fr0/fr1 in fr0; from C, the arc tangent of x/y is returned. The range is -π to π. DIAGNOSTIC There is no error return. BUGS