(3). You are given the function 8(x) = 12x + 30x4 - 300x3 + 120 (a) (5 points) Find all critical points of this function. You must show work justifying your conclu sions. (b) (6 points) Classsify all critical points of this function as to whether they are local minima, local maxima, or neither. You must show work justifying your conclusions. (continued on next page) Math 1131 - Autumn 2021 Exam 3 - Written Portion Page 6 of 6 Problem (3), continued (c) (6 points) Determine the x-value of the global (absolute) maximum of this function on the inter- val [0, 4]. If there is none, say so. You must show work justifying your conclusions