Maths Problem

[xChrisVx]

Hi, I have this maths problem in my homework which is due in tomorrow:

A cylindrical container, open at the top has a volume of 64π cubic centimeters and a height of h centimetres.

(a) Show that h = 64/r^2

(b) If the radius of the container is r cm, show how the total surface area, A, of the container can be represented by the function:

A(r) = 128π/r + πr^2

Help is greatly appreciated

Thanks

[Sonic Boom]

Hey there :) I think you left out pi in both answers :P

a) Volume of a cylinder = h x pi x r^2

V= 64 = h x pi x r^2
So h = 64/pi.r^2

b) Surface area of a cylinder = A(r)= (2pi x r^2) + (2pi x r x h)

= 2V/h + 2V/r
= (2 x 64)/h + (2 x 64)/r

= [64 x pi x r^2] + 128/r

Hope these make sense.

[xChrisVx]

Got them done! Thanks for the help.