The cylinder is a clue to use cylindrical coordinates. Taking

and

, we then are forced to use

. So the parameterization of the intersection of the plane and cylinder is

To get the surface, we can introduce a second parameter

that "contracts" the elliptical intersection to a point. The simplest way to do this is to use

with

and

.
Your answer will be 7.50. What I did was take 1.25 and times it by 6.
Answer: D
Step-by-step explanation:
not sure what the dots are supposed to mean..
but i think it's 6B5??
Answer:

Step-by-step explanation:
