Show work please

6. Researchers determined that the concentration of a medication in a patient's bloodstream 96t hours after it was administered can be approximated by p(t) = 7 2 + 6 percent concentration on the interval [1, 20]. a. Find the t-coordinate of the critical point(s) on the given interval. b. Suppose you perform the 20 derivative test to determine if the critical point(s) found in part a is a maximum or a minimum, and this is your result, p"(CP) =-3.268. (CP stands for "Critical Point" from part a.) Clearly explain how to interpret this value regarding whether the CP found is a local maximum or minimum