For an infinite cylinder dV=2*pi*r*L*dr
Would dv=pi*L*r*dr for a finite cylinder?
Explain this in words, to show that you understand it and how it arises.
Yes, this definitely still holds;
I could also refer you here, for the proof:http://en.wikipedia.org/wiki/Cylinder_(geometry)#Volume"
Beware that an infinite cylinder carries, A volume per unit length, or, L is unknown...
Both formulae are correct and useable...
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