TAN(3M) | Mathematical Library Functions | TAN(3M) |

tan, tanf, tanl - tangent function

c99 [flag... ]file...-lm[library... ] #include <math.h>doubletan(doublex);

floattanf(floatx);

long doubletanl(long doublex);

These functions compute the tangent of their argument *x*,
measured in radians.

Upon successful completion, these functions return the tangent of
*x*.

If *x* is NaN, a NaN is returned.

If *x* is ±0, *x* is returned.

If *x* is ±Inf, a domain error occurs and a NaN is
returned.

These functions will fail if:

**Domain Error**

The value of *x* is ±Inf.

If the integer expression (**math_errhandling** &
**MATH_ERREXCEPT**) is non-zero, the invalid floating-point exception is
raised.

There are no known floating-point representations such that for a
normal argument, **tan**(*x*) is either overflow or underflow.

An application wanting to check for exceptions should call
**feclearexcept**(**FE_ALL_EXCEPT**) before calling these functions.
On return, if **fetestexcept**(**FE_INVALID** | **FE_DIVBYZERO** |
**FE_OVERFLOW** | **FE_UNDERFLOW**) is non-zero, an exception has been
raised. An application should either examine the return value or check the
floating point exception flags to detect exceptions.

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE | ATTRIBUTE VALUE |

Interface Stability | Standard |

MT-Level | MT-Safe |

math.h(3HEAD), atan(3M), feclearexcept(3M), fetestexcept(3M), isnan(3M), attributes(7), standards(7)

July 12, 2006 | SunOS 5.11 |