- #1
Karol
- 1,380
- 22
Homework Statement
Homework Equations
Maxima/minima are where the first derivative is 0
The Attempt at a Solution
Surface area of the whole metal for creating the can (the end pieces i take as squares):
$$A=2\pi h+8r^2,~~V=\pi r^2 h~~\rightarrow~h=\frac{V}{\pi r^2}$$
$$A=2\pi \frac{V}{\pi r^2}+8r^2,~~A'=2V(-2)r^{-3}+16r=16r-\frac{4V}{r^3}$$
$$A'=0~\rightarrow~4r^4=V$$
I can't get rid of the volume V