On success, these functions return the tangent of
x.

If
x is a NaN, a NaN is returned.

If
x is positive infinity or negative infinity,
a domain error occurs,
and a NaN is returned.

If the correct result would overflow,
a range error occurs,
and the functions return
HUGE_VAL,
HUGE_VALF, or
HUGE_VALL, respectively, with the mathematically correct sign.

This page is part of release 3.44 of the Linux
man-pages project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.