Sine Identity

In the applet below, the graph of the function [math]f\left(x\right)=sin\left(x\right)[/math] is displayed. [br][br]Place the BIG WHITE POINT anywhere you'd like prior to sliding the slider. [br][br]Answer the questions that follow.
Write a new trigonometric identity that expresses the relationship between [math]sin\left(-x\right)[/math] and [math]sin\left(x\right)[/math].
What else can you conclude about the parent sine function [math]f\left(x\right)=sin\left(x\right)[/math]? [br]For a hint, [url=]click here[/url].
Quick Demo: 0:00 sec to 0:36 sec (BGM: Andy Hunter)

Information: Sine Identity