The attached application shows you how to calculate the trigonometric functions arcsen and arccos according to the value typed by the user.
When the application is running, type a certain value at Type value between -1 and 1 setpoint, and then click either Cosine Arc or Sine Arc button. The result will be shown at Answer in Degrees display.
To understand how these calculations were made, check the scripts for Cosine Arc and Sine Arc buttons.