tandg

Circular tangent of argument in degrees.

SYNOPSIS:

double x, y, tandg();
y = tandg(x);

DESCRIPTION:

Returns the circular tangent of the argument x in degrees.
Range reduction is modulo pi/4. A rational function:
       x + x**3 P(x**2)/Q(x**2)
is employed in the basic interval [0, pi/4].

ACCURACY:
                      Relative error:
arithmetic   domain     # trials      peak         rms
    DEC      0,10          8000      3.4e-17      1.2e-17
    IEEE     0,10         30000      3.2e-16      8.4e-17

ERROR MESSAGES:

message             condition        value returned
total loss       x > 8.0e14 (DEC)        0.0
                  x > 1.0e14 (IEEE)
singularity      x = 180 k + 90        MAXNUM