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

Chapter 5 125
HP C/iX Library Function Descriptions
cos
cos
Computes a cosine value for a given angle.
Syntax
#include <math.h>
double cos (double x );
Parameters
x A real number giving the angle measured in radians.
Return Value
n The cosine of the angle.
0 A complete loss of significance. A TLOSS error message is printed on the
standard error output. The external variable errno is set to ERANGE.
Description
The cos function returns the cosine of its argument, x , measured in radians.
This function loses accuracy when its argument is far from zero. 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(), tan(), matherr(), ANSI C 4.5.2.5, POSIX.1 8.1