lllJ lJl Determine the open intervals on which the graph is concave upward or concave downward. [Enter your answers using interval notation. If an answer does not exist, enter DNE.) x7 x}= 7 concave upward concave downward x+4 DNE Need rue-p? Find the point of inflection of the graph of the function. (If an answer does not exist, enter DNE.) f(x) = x - 3x2+ 29x - 27 (x, y) = Describe the concavity. (Enter your answers using interval notation. If an answer does not exist, enter DNE.) concave upward concave downward