Part a: Assume that the height of your cylinder is 8 inches. Think of A as a function of r, which we may express as . What is the domain of ? In other words, for which values of r is defined?
Part b: Find the inverse function to . Your answer should look like "some expression involving A".
Hints:
1) You must find r to calculate an inverse function.
2)Here you could start with . This equation is the same as . Do you recognize this as a quadratic equation where the variable x is r? The coefficients would be for a, for b, and for c.
3)You can solve for r using the quadratic formula even though the constant term c is a symbol here.
Part c: If the surface area is 225 square inches, then what is the radius r? In other words, evaluate . Round your answer to 2 decimal places.
Need Part A