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math.acosh

Available inall subroutines.

Computes the inverse hyperbolic cosine of its argument x.

Parameters

x - Floating point value representing the area of a hyperbolic sector.

Return Value

Upon successful completion, this function returns the inverse hyperbolic cosine of x.

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

If x is +1, +0 will be returned.

If x is math.POS_INFINITY, math.POS_INFINITY will be returned.

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

For finite values of x < 1, a domain error occurs and a NaN will be returned.

Errors

If the x argument is finite and less than +1.0, or is math.NEG_INFINITY, then fastly.error will be set to EDOM.

Example

declare local var.fo FLOAT;

set var.fo = math.acosh(10);