Quote Originally Posted by ceecee79
I need some help with 2 math problems from my math class. I used to be good in math, and still am, in some areas, like probability, which I can use in poker, but not so much in other areas, like geometry.

I have until Tuesday to turn these in, so if anyone can help, and explain, it would be greatly appreciated.

1. A steel drum in the shape of a right circular cylinder is required to have a volume of 100 cubic feet.

V=(pi)(radius^2)(height) so substitute for Volume as 100 and
100 = (pi)(radius^2)(height)

a) express the amount of material needed to make the cylinder as a function of the radius

All your doing here is solving for variables: r(adius) or h(eight)
100
(pi)(h) = r(adius) ^2

With the answer you get from above, square root the answer, and that is the function for r.

b) what radius gives the least amount of material?
Use your brains and calculate it out just punching numbers basically to solve for the V=100

c) what is the least amount of material needed for such a radius?
See B

2. A sprinkler that sprays water in a circular motion is to be used to water a square garden. If the area of the garden is 920 sq. ft. find the smallest whole number radius that the sprinkler can be adjusted to so that the entire garden is watered. Also determine how much area outside the garden is watered?
Square garden. So a square has 4 equal sides, and the equation for the area of a square is s(ide) squared.

Area of a circle equation : (pi)(radius squared)

If you can help, please do, and don't just give me the answer, please explain as well.

Thanks
See Above