My brain is not working can someone give me a hand?

[MrJoe2000]

Okay so I have a differential problem but I just can't seem to finish it off...

I have a cylinder whose diameter is 10 when it's height is 20. If the diameter is increasing by 1, then how is the height changing to keep the volume constant?

I take the differential of the volume equation but I can't figure out what to do from there. Can someone help me out?

 

[Deleted member 4993]

Okay so I have a differential problem but I just can't seem to finish it off...

I have a cylinder whose diameter is 10 when it's height is 20. If the diameter is increasing by 1, then how is the height changing to keep the volume constant?

I take the differential of the volume equation but I can't figure out what to do from there. Can someone help me out?

I do not understand what you meant by - "I take the differential of the volume equation". Volume is constant according to the problem.

Please share your work with us, so that we know where to begin to help you.

 

[MrJoe2000]

Figured it out

You solve the problem by taking the derivative of the volume equation and setting dV/dt to zero.

 

[pka]

You solve the problem by taking the derivative of the volume equation and setting dV/dt to zero.

\(\displaystyle V=\pi r^2 h\) so \(\displaystyle \dfrac{dV}{dt}=~?\)

 

[srmichael]

And since they give you the rate that the diameter is changing, you may want to first rewrite the volume formula in terms of "d" (diameter) instead of radius before you find \(\displaystyle \frac{dV}{dt}\)