THE SURFACE AREA IS 3220CM^2
Well, he would use 4/4 cup of cranberry juice to equal 1 cup. that is 4x the original amount. so, multiply 1/2 × 4 to equal 2 cups. David would use 2 cups of apple juice for every 1 cup of cranberry juice.
Your answer is y=15 for your problem
Each curve completes one loop over the interval

. Find the intersections of the curves within this interval.

The region of interest has an area given by the double integral

equivalent to the single integral

which evaluates to

.