John,
This can be solved by creating a java action that returns the result from the formula you're using and then call this java action from within the microflow, because as far as I know there is no sine and cosine function available in a microflow action.
Create a JavaAction with parameter Degree and result Float.
Put this between begin end user code
// BEGIN USER CODE
return Math.sin(Math.toRadians(Degrees));
// END USER CODE
for radians remove the toRadians