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. To use this function, compile either with the −Ae option or with the −Aa and −D_HPUX_SOURCE options. Otherwise, the compiler promotes the float argument to double, and the function returns incorrect results.

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, 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

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

[ERANGE] The correct value would overflow.

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