Graph y1 = x2 − 2x, y2 = x, and y3 = y1 ÷ y2 in the same [−10,10,1] by [−10,10,1] viewing...

Graph y1 = x2 − 2x, y2 = x, and y3 = y1 ÷ y2 in the same [−10,10,1] by [−10,10,1] viewing rectangle. Then use the  feature to trace along y3. What happens at x = 0? Explain why this occurs.