The arc-cosecant is the inverse of the cosecant function. Calcute implements it with the acsc function. The inverse cosecant of a value x is the value y for which the cosecant of y is x. In other words if y = acsc(x) then x = csc(y). And since the cosecant takes an angle as input parameter, the arccosecant produces an angle as its output.
acsc(1) 1.57079632679
The acsc value is expressed by Calcute using the currently-selected angle unit: radian, degree or gradient. In the above example, the result is in radians.
The arc-cosecant function is undefined in the open range
In some mathematical texts and hand-held calculators, the notation csc-1 is sometimes used to represent the arc-cosecant function. This is an unfortunate notational choice since it could also stand for the multiplicative inverse 1/csc, which is a different function.
Yet another term also used to represent the inverse cosecant function is "arccsc".