tan(3M)

DESCRIPTION

tan() returns the tangent of x (x specified in radians).

tan() may lose accuracy when x is far from zero.

tanf() is a float version of tan(); it takes a float argument and returns a float result. To use this function, compile either with the default -Ae option or with the -Aa and -D_HPUX_SOURCE options.

tanf() is not specified by any standard, but it is named in accordance with the conventions specified in the "Future Library Directions" section of the ANSI C standard.

To use these functions, make sure your program includes <math.h>, and link in the math library by specifying -lm on the compiler or linker command line.

Millicode versions of the tan() and tanf() functions are available. Millicode versions of math library functions are usually faster than their counterparts in the standard library. To use these versions, compile your program with the +Olibcalls or the +Oaggressive optimization option.

If an error occurs, the millicode versions return the value described in the RETURN VALUE section, but do not set errno.

For more information, see the HP-UX Floating-Point Guide.

RETURN VALUE

If x is NaN or ±INFINITY, tan() returns NaN.

If the correct value after rounding would be smaller in magnitude than MINDOUBLE, tan() returns zero.

If the correct value would overflow, tan() returns ±HUGE_VAL and sets errno to [ERANGE].

ERRORS

If tan() fails, errno is set to the following value.

SEE ALSO

acos(3M), asin(3M), atan(3M), atan2(3M), cos(3M), sin(3M), tand(3M), math(5), values(5).

STANDARDS CONFORMANCE

tan(): SVID3, XPG4.2, ANSI C