HP-UX Reference (11i v1 05/09) - 3 Library Functions N-Z (vol 7)

tand(3M) tand(3M)

NAME

tand(), tandf() - degree-valued tangent functions

SYNOPSIS

#include <math.h>

double tand(double x);

float tandf(float x);

DESCRIPTION

tand() is a degree-valued version of the

tan() function. It returns the tangent of x (x speciﬁed in

degrees).

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

tandf() is a float version of tand()

; it takes a float argument and returns a float result.

tand() and tandf() are not speciﬁed by any standard, but

tandf() is named in accordance with the

conventions speciﬁed in the "Future Library Directions" section of the ANSI C standard.

To use these functions, compile either with the default

-Ae option or with the -Aa

and

-D_HPUX_SOURCE options. Make sure your program includes <

math.h>. Link in the math library by

specifying

-lm on the compiler or linker command line.

RETURN VALUE

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

If the correct value after rounding would be smaller in magnitude than

MINDOUBLE, tand() returns

zero.

If the correct value would overﬂow,

tand() returns ±HUGE_VAL and sets errno to [ERANGE].

ERRORS

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

[ERANGE] The correct value would overﬂow.