Hello there :) I'm having tons of trouble figuring out how to finish this problem. A cone is to be constructed having a given slant height of l>0 . Find the radius and height which give maximal volume. I am unsure of which variables to keep in order for it to be maximized, and how to go about optimizing it. This is how I was going about it: I think that the cross-section of the cone makes a right angled triangle, for which the equation would be l^2= b^2 + h^2, and in order to maximize the volume you must relate it to the volume equation V = 1/3(pi)r^2h, but I am having trouble putting it together, to be able to differentiate and then maximize.