Find the point of inflection of the graph of the function. (If an answer does not exist, enter DNE.) (x, y) = f(x) = x3 − 6x2 + 13x Describe the concavity. Concave upward: (−∞, 2) (−∞, −2) (2, ∞) (−2, ∞) none of these Concave downward: (−∞, 2) (−∞, −2) (2, ∞) (−2, ∞) none of these