Ok, In my calc book I am having problem with the first example they give in a chapter on Differentiation.(adsbygoogle = window.adsbygoogle || []).push({});

It gives the equation of [itex]V = \frac{4}{3} \pi r^3[/itex] and then it is differentiated by time = t.

[tex]\frac{dV}{dt} = \frac {dV}{dr} \frac{dr}{dt} = 4 \pi r^2 \frac {dr}{dt}[/tex]

I dont quite understand why the chain rule is being used in the first place, because [itex]4 \pi r^2[/itex] doesn't need it, and also I dont understand where [itex]\frac{dr}{dt}[/itex]comes from in the last part. Im quite confused by this basic stuff [b(] so thanks for any help.

edit : \/ Thanks for the help getting it to show up right :)

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# Basic differentiation?

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