(TIMED TEST) Use the graph of the function to estimate intervals on which the function is increasing, decreasing, or constant. Support the answer numerically. From the graph, it appears that: A function f(x) = -1/2 x^2 + x + 4 is decreasing for _. A function f(x) = -1/2 x^2 + x + 4 is increasing for _. The critical points is _.