Vector Subtraction (3D)

[b]Observe the Applet below. You may freely move points around and click the buttons.[/b]
[b]What are the coordinates of the position vector [math]-\vec{OB}[/math]?[br][br]How would you use this to compute the position for [/b][math]\vec{OA}-\vec{OB}[/math][b]? Briefly explain.[/b]

Information: Vector Subtraction (3D)