math.acos
Available inall subroutines.
Computes the principal value of the arc cosine of its argument x
.
Parameters
x
- Floating point value. The value of x
should be in the range -1 to 1
inclusive.
Return Value
Upon successful completion, this function returns the arc cosine of x
in the
range 0 to math.PI
radians inclusive.
If x
is math.NAN
, a NaN will be returned.
If x
is +1, +0 will be returned.
If x
is math.POS_INFINITY
or
math.NEG_INFINITY
, a domain error occurs
and a NaN will be returned.
For finite values of x not in the range -1 to 1 inclusive, a domain error occurs and a NaN will be returned.
Errors
If the x
argument is finite and is not in the range -1 to 1 inclusive,
or is math.POS_INFINITY
or
math.NEG_INFINITY
,
then fastly.error
will be set to EDOM
.
Example
declare local var.fo FLOAT;
set var.fo = math.cos(1.1); // Returns math.NAN
if (fastly.error) { set resp.http.acos-error = fastly.error; // Returns "EDOM"}