Returns the arcsine, or inverse sine, of a number. The arcsine is the angle whose sine is number. The returned angle is given in radians in the range -pi/2 to pi/2.
Syntax
ASIN(number)
Number    is the sine of the angle you want and must be from -1 to 1.
Remark
To express the arcsine in degrees, multiply the result by 180/PI() or use the DEGREES function.
Examples
| 
                   Formula  | 
                
                   Description (Result)  | 
              
| 
                   =ASIN(-0.5)  | 
                
                   Arcsine of -0.5 in radians, -pi/6 (-0.5236)  | 
              
| 
                   =ASIN(-0.5)*180/PI()  | 
                
                   Arcsine of -0.5 in degrees (-30)  | 
              
| 
                   =DEGREES(ASIN(-0.5))  | 
                
                   Arcsine of -0.5 in degrees (-30)  |