4.5 Derivatives and Shapes of Graphs: Problem 8 (1 point) Results for this submission Entered (0, 3) (-infinity,0), (3,infinity) 3 At least one of the answers above is NOT correct. Answer Preview (0, 3) (-0, 0), (3,00) 3 Let f(x) = x - 9x + 7x - 8. Find the open intervals on which f is concave up (down). Then determine the x-coordinates of all inflecti 1. f is concave up on the intervals 2. f is concave down on the intervals 3. The inflection points occur at x = 3 Notes: In the first two, your answer should either be a single interval, such as (0,1), a comma separated list of intervals, such as (-inf, 2), (3 In the last one, your answer should be a comma separated list of a values or the word "none