====== Inverse Sine (Expression Function) ======

===== Purpose =====
The **Inverse Sine** function (ASIN) is used to calculate the inverse, arc, [[Expression Function - Sine|sine]] in radians, degrees, or gradians. 

{{::asin_initial.png?direct&600|}}

===== Parameters =====
The **Inverse Sine** function has two parameters, the first of which is required:

==== Value ====

Allowed Inputs: [[Field|field]] value or number

The first required parameter is the value that the inverse sine will be obtained from either use the use the [[Query Builder]] to choose a field that contains the value or use type a value to enter a number.

==== Angle Unit ====

Allowed Inputs: omitted, 'd', 'g' 

The second parameter of the **Inverse Sine** function is the unit of the angle output. If the angle unit is omitted or not recognized then radians will be be used.  For an angle provided in degrees use 'd'.  For an angle provided in gradians use 'g'.  If the angle unit needs to be dynamically stored in a field then the advanced expression builder will need to be used.


===== Output =====

The output of the **Inverse Sine** function is a number representing the arc sine of the angle in radians, degrees, or gradians.

===== Example =====

For example ASIN(0.5) is "0.523598775598", ASIN(0.5,'d') is "30", and ASIN(0.5,'g') is "33.3333333333".