The rule for quotients of similar bases with different exponents is:
(a^c)/(a^b)=a^(c-b) in this case:
15^18/(15^3)=15^15
So Volume of cylinder is pi*r^2*h = 1,000
Then lightest one means you have the smallest surface area. Which is one base and then the area of the surface. SA = pi*r^2 + 2pi*r*h
So now you have 2 equations, so:
h = 1,000/(pi*r^2)
So then SA = pi*r^2 + 2pi*r*(1,000/(pi*r^2) = pi*r^2 + 2,000/r
Derivative of SA is then 2pi*r -2,000/r^2. Set to 0
2pi*r-2,000/r^2 =0 --> 2pi*r^3 = 2,000 --> r^3 = 1,000/pi --> r = 10/pi^(1/3)
Now go back to the volume function: pi*r^2*h =1,000 --> 1,000/(pi*100/pi^(2/3)) = h
<span>h = 10 / pi^(1/3)</span>
I belive what you did wrong is that you didint show your work so what you have to do is explain how to do the problem with equations or explain in word form if i were you i would show my work in equations if you need help on how to set it up contact me.
