4. COnsider the circular c0ne 4cm (a) Use the diagram to nd an equation for 'r in terms of h. (b) Find the mathematically implied domain for the function r(h). ) ) (c ((1 Given the volume of a circular cone is Find the physically implied domain for r(h). Make sure you explain your answer. V = rzh use your result in part (a) to express V in terms of h. (e) Find all the critical values of V for h E dom(r), as found in part (b). Determine the nature of each critical value using the second derivative test. (f) For the physical problem, what is the maximum volume this cone can have, and what is its corresponding height? Make sure you show this is a global maximum. (Q4: 2+1+2+1+6+4=16 marks)