Refer to the graph of shown in the following figure_
10 H1 12
(a) Find the intervals where is concave upward and the intervals where is concave downward_ (Enter vour answers using interval notation.)
concave upward
concave downward
(b) Find the inflection points of f. (Order your answers from smallest to largest x, then from smallest to largest Y. If an answer does not exist, enter DNE.)
(x,Y)
(X,Y)
(x,Y)