ASIN function
This article describes the formula syntax and usage of the ASIN function in Microsoft Excel.
Description
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)
The ASIN function syntax has the following arguments:

Number Required. 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.
Example
Copy the example data in the following table, and paste it in cell A1 of a new Excel worksheet. For formulas to show results, select them, press F2, and then press Enter. If you need to, you can adjust the column widths to see all the data.
Formula 
Description 
Result 
=ASIN(0.5) 
Arcsine of 0.5 in radians, pi/6 
0.523598776 
=ASIN(0.5)*180/PI() 
Arcsine of 0.5 in degrees 
30 
=DEGREES(ASIN(0.5)) 
Arcsine of 0.5 in degrees 
30 