Is [math]y=\cos x[/math] a one-to-one function?

Move the left slider to a point on the left and the right slider to a [br]point on the right where the highlighted portion of the graph is [br]one-to-one.[br][br]What restriction should be used so that [math]y=\cos x[/math] is one-to-one and the full range of the function is used?