The slider on the left hand side will give you a hint how to go about the question. But first try to work it out with your pair, then check the answer by sliding the slider to bit by bit,

By dragging the brown dots any direction you wish, you can change the sloppiness and the length of the line segment. For every change you make investigate what is happening to the gradient of the line.[br]You may first guess with friend what kind of gradient you are going to get. Then do the actual calculations, find the answer and share with the class what you have understood.[br][br]