We often take the SINE, COSINE, or TANGENT of an ANGLE. Thus, for these 3 main trigonometric functions, we [b]INPUT an ANGLE[/b], and [b]get an OUTPUT that is a RATIO[/b] (the sine, cosine, or tangent ratio). [br][br]Yet the INVERSE TRIGONOMETRIC FUNCTIONS literally UNDO what the trigonometric functions do. [br]Thus, here, we [b]INPUT a RATIO[/b] and get an [b]OUTPUT that is an ANGLE[/b]. [br][br]Interact with this GeoGebra resource below to see this in action.[br]Here, you can select to display the graph of the [b][color=#9900ff]inverse sine function[/color][/b], [color=#cc0000][b]inverse cosine function[/b][/color], or [b][color=#0000ff]inverse tangent function[/color][/b]. [br][br][b]Note:[/b] [br]The inverse trigonometric functions are also called the [b][color=#9900ff]ARCsine[/color][/b], [b][color=#cc0000]ARCcosine[/color][/b], and [b][color=#0000ff]ARCtangent[/color][/b] functions. Note ARC is synonymous for ANGLE. These functions always output an ANGLE.