Part a: Assume that the height of your cylinder is 4 inches. Consider A as a function of r , so we can write that as A(r)=2r2 8r . What is the domain of A(r) ? In other words, for which values of r is A(r) defined? Part b: Continue to assume that the height of your cylinder is 4 inches. Write the radius r as a function of A . This is the inverse function to A(r) , i.e., to turn A as a function of r into r as a function of A . r(A)= Preview Change entry mode Hints: To calculate an inverse function, you need to solve for r . Here, you would start with A=2r2 8r . This equation is the same as 2r2 8rA=0 which is a quadratic equation in the variable r , and you can solve that using the quadratic formula. You will want to keep A as a variable when you plug the values into the quadratic formula. If you want to type in 3 1x 1 in Mobius, in text mode you can type in (3*pi 1)/(x 1). There is more information in the Introduction to Mobius unit. Part c