I have 2 word problems that I am having trouble with:
The surface area of a cylindrical can of radius r and height h is
2pi r squared + 2pi r h. If the can is twice as high as the diameter of its top, express its suface areqa S as a function of r.
A rectanular region of 6000 square feet is to be fenced in on three sides with fencing that costs $3.75 per foot and on the fourth side with fencing that costs $2.00 per foot.
a. Express the cost of the as a function a function of the length x of the fourth side.
b. Find the domain of the function.
Any help would be greatly appreciated.