The ASIN function returns a numeric value in radians that approximates the arcsine of
`argument-1`. The type of this function is numeric.

FUNCTIONASIN(argument-1)

`argument-1`must be class numeric.- The value of
`argument-1`must be greater than or equal to`-1`and less than or equal to`+1`.

Note: This function will produce results accurate to only about 17 digits, even when
`argument-1` contains more than 18 digits (for example, if you have compiled your program for 31-digit support.)

The returned value is the approximation of the arcsine of
`argument-1` and is greater than or equal to
`-pi/2` and less than or equal to
`+pi/2`.