Also can you d too D) find the local maximum and or minimum for the function and please explain how you know which is which

4. For this problem, recall that you are not allowed the use of a graphing calculator. If a graph appears as if from nowhere and you use it to do this problem you will receive a zero on the entire exam. If you use analytical methods to graph this function that's ne, but it must be completely clear how you produced the graph without using a graphing calculator. If you state the answers without any work I will assume you used a graph generated by using a resource that is not allowed and I will give you a zero on this exam. Let f($) = 9:4 2352 + 3. (a) (5 points) Find the critical points of f. (b) (4 points) Find the intervals where the function is increasing/decreasing. Reasoning must be shown. (c) (4 points) Find the intervals where the function is concave up/concave down. Reasoning must be shown