Let f(x) = a(x-1)(x+1) where is some unknown number. How many turning points will the graph y = f(x) have? Does it depend on the value of a? For following questions assume a > 0 Is the vertex above the x-axis or below the x-axis? If the vertex has coordinates (h, k) is k> 0 or k < 0 ? Assuming the vertex is at (0, -4), find the value of a (Note: this means f(0) = -4) If you are stuck, solve the equation -4=-a. Why is this equation relevant?