Graph each function given below on a graphing calculator to find a general rule for determining when a graph crosses the x axis at an x intercept or when the graph just touches and turns away from the x axis. State the rule that you find. [3]

y = (x + 1)^2(x - 2)

y = (x - 4)^3(x - 1)^2

y = (x - 3)^2(x + 4)^4