5) An open-top rectangular tank that has a square base x feet on one side and a height of y feet is to be built with its top flush with the ground to catch runoff water. The material used to make the tank costs 50 dollars per square foot. In addition to the material cost, there is an excavation cost to install the tank below the ground and the excavation cost is 10m; dollars. The volume of the tank must be 1125 cubic feet. a) Draw a diagram of this tank with the dimensions labeled in terms of x and y. b) Construct the equation for the total cost C(x) of this tank. C(x) = c) Find the values of x and y that will minimize the cost. Show your calculation of the derivative of Clx) with respect to x