



 
Hi Barbara, The volume of a cone of radius r cm and height h cm is given by
V, r and h are all functions of time and you are told that dr/dt = dh/dt = 2 cm/s. What you want is dV/dt when r = 10 cm and h = 20 cm. Differentiate V = 1/3 π r^{2} h implicitly with respect to t and you will see that you know the value of each of the variables except dV/dt. Solve for dV/dt. Harley  


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