Futurebasic/Language/Reference/asin

Function
✔ Appearance ✔  Standard ✔  Console

Syntax
radianAngle# = asin( expr )

Description
Returns the arcsine of  in radians. In other words, if  represents the sine of some angle, then      returns the angle. The returned angle will be in the range of -π/2 to +π/2 radians (which corresponds to -90 to +90 degrees). always returns a double-precision result.