HP C/iX Library Reference Manual (30026-90004)

360 Chapter5
HP C/iX Library Function Descriptions
tan
tan
Computes a tangent value.
Syntax
#include <math.h>
double tan (double x )
Parameters
x A real number giving the angle measured in radians.
Return Values
n The tangent of the angle.
0 Indicates a complete loss of accuracy for large values of
x . A TLOSS error
message is printed on the standard error output. errno is set to ERANGE.
Description
The tan function returns the tangent of its argument x , measured in radians. This
function loses accuracy when its argument is sufficiently large. For less extreme
arguments causing partial loss of significance, a PLOSS error is generated but no message
is printed and errno is set to ERANGE.
Error handling can be changed by a user-written matherr function.
See Also
sin(), cos(), ANSI C 4.5.2.7, POSIX.1 8.1