tan

Circular tangent.

SYNOPSIS:

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

DESCRIPTION:

Returns the circular tangent of the radian argument x.
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      +-1.07e9      44000      4.1e-17     1.0e-17
    IEEE     +-1.07e9      30000      2.9e-16     8.1e-17

ERROR MESSAGES:

message          condition          value returned
total loss     x > 1.073741824e9         0.0