sin, cos, tan, asin, acos, atan, atan2 - trigonometric functions
The subroutines and return trigonometric functions of radian arguments.
The magnitude of the argument should be checked by the caller to make
sure the result is meaningful.
The subroutine returns the arc sin in the range -π/2 to π/2.
The subroutine returns the arc cosine in the range 0 to π.
The subroutine returns the arc tangent of x in the range -π/2 to π/2.
The subroutine returns the arc tangent of x/y in the range -π to π.
The value of for arguments greater than about 2**31 is unreliable.
Arguments of magnitude greater than 1 cause and to return zero and set
errno to EDOM.
The function returns zero and sets errno to EDOM when x and y are both
When your program is compiled using the System V environment, and lose
accuracy when their argument is far from zero. For arguments suffi‐
ciently large, these functions return 0 when there would otherwise be a
complete loss of significance. In this case a message indicating TLOSS
error is printed on the standard error output. For less extreme argu‐
ments, a PLOSS error is generated but no message is printed. In both
cases, errno is set to ERANGE.
The subroutine returns HUGE for an argument which is near an odd multi‐
ple of π/2 when the correct value would overflow, and sets errno to
Arguments of magnitude greater than 1.0 cause and to return 0 and to
set errno to EDOM. In addition, a message indicating DOMAIN error is
printed on the standard error output.
These error-handling procedures may be changed with the function