Explain how you got the answer, please.

The height of the cylinder is 4 inches. We'll be analyzing the surface area of a round cylinder - in other words, the amount of material needed to "make a can" A cylinder (round can) has a circular base and a circular top with vertical sides in between Let r be the radius of the top of the can and let h be the height. The surface area of the cylinder, A, is A = 2nr2+ 2urh (two circles, one for the top and one for the bottom plus a rolled up rectangle for the sides). r = radius Areas = 1 12 h = height Area = h(2mr) Circumference 2AT 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) -2 mr + 8 mr. What is the domain of A (r)? In other words, for which values of T 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. (A) Hints: To calculate an inverse function, you need to solve for . Here, you would start with A# 2 mr + 8 mr. This equation is the same as 2 mr- + 8 ar - A - 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 Pin Mobius, in text mode you can type in (3*pit1)/(x+1). There is more information in the Introduction to Mobius unit. Part c: If the surface area is 125 square inches, then what is the radius r? In other words, evaluate T (125) Round your answer to 2 decimal places. Hint: To compute a numeric square root such as v17.3, you could Use a spreadsheet such as Microsoft Excel or OpenOffice Calc and type in =sqrt(17.3) Use a browser to connect to the Internet and type in sqit(17.3) into a search field Previous Unit Item Next Unit Item