c/numeric/math/tan

@1-6@ Computes the tangent of  (measured in radians). @7@ Type-generic macro: If the argument has type,  is called. Otherwise, if the argument has integer type or the type,  is called. Otherwise,  is called. If the argument is complex, then the macro invokes the corresponding complex function (ctanf, ctan, ctanl).

Return value
If no errors occur, the tangent of ($tan(arg)$) is returned.

If a domain error occurs, an implementation-defined value is returned (NaN where supported).

If a range error occurs due to underflow, the correct result (after rounding) is returned.

Error handling
Errors are reported as specified in.

If the implementation supports IEEE floating-point arithmetic (IEC 60559):
 * if the argument is ±0, it is returned unmodified;
 * if the argument is ±∞, NaN is returned and fe_invalid is raised;
 * if the argument is NaN, NaN is returned.