math.asin()

Computes the principal value of the arc sine of the 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 sine of x, in the range -math.PI_2 to math.PI_2 radians inclusive.

If x is math.NAN, a NaN will be returned.

If x is ±0, x will be returned.

If x is math.POS_INFINITY or math.NEG_INFINITY, a domain error occurs and a NaN will be returned.

If x is subnormal, a range error occurs and x 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.
• If the x argument is subnormal, then fastly.error will be set to ERANGE.

Format

FLOAT
math.asin(FLOAT x)

Examples

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declare local var.fo FLOAT;

set var.fo = math.asin(1.0);