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nnnnnn

Guest Nov 21, 2018
edited by Guest  Nov 21, 2018

Best Answer 

 #1
avatar+3190 
+2

\(V=\dfrac 4 3 \pi r^3\\ \dfrac{dV}{dr} = 4 \pi r^2\\ \text{ok a bit of magic here}\\ dV = 4\pi r^2 dr\\ \dfrac{dV}{dt} = 4\pi r^2 \dfrac{dr}{dt} \\ 2 = 4 \pi (3)^2 \dfrac{dr}{dt}\\ \dfrac{dr}{dt} = \dfrac{1}{18\pi}~in/hr\)

Rom  Nov 21, 2018
 #1
avatar+3190 
+2
Best Answer

\(V=\dfrac 4 3 \pi r^3\\ \dfrac{dV}{dr} = 4 \pi r^2\\ \text{ok a bit of magic here}\\ dV = 4\pi r^2 dr\\ \dfrac{dV}{dt} = 4\pi r^2 \dfrac{dr}{dt} \\ 2 = 4 \pi (3)^2 \dfrac{dr}{dt}\\ \dfrac{dr}{dt} = \dfrac{1}{18\pi}~in/hr\)

Rom  Nov 21, 2018
 #2
avatar+352 
0

Hi Guest, 

 

You should not delete your question, because other people may have that question as well.

 

- Daisy

dierdurst  Nov 21, 2018
 #3
avatar+656 
+2

nnnnnn? Why did you delete your question? Other people may have the same or similar questions. 

PartialMathematician  Nov 22, 2018
 #4
avatar+3190 
0

The question was:

 

A balloon is losing 2 cubic inches of air per hour.

 

At what rate is it's radius decreasing when the balloon is 3 inches in radius.

Rom  Nov 23, 2018

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