Which statements are true about the graph of the function f(x) = 6x – 4 x2? check all that apply. the vertex form of the function is f(x) = (x – 2)2 2. the vertex of the function is (–3, –13). the axis of symmetry for the function is x = 3. the graph increases over the interval (–3, ). the function does not cross the x-axis.