Math Is Fun Forum

taylor_2009

Member

Registered: 2010-01-25

Posts: 28

How fast is volume changing?

The volume V of a spherical cancer tumor is given by V = [pi]x³/6, where x is the diameter of the tumor. A physician estimates that the diameter is growing at a rate of .4 millimeters per day, at a time when the diameter is already 10 millimeters. How fast is the volume of the tumor changing at that time?

I'm not sure how to solve this. I know that .4 is dx/dt but I don't know how to find dV/dt because only one equation is given.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: How fast is volume changing?

Hi taylor_2009;

the diameter is growing at a rate of .4 millimeters per day,

Did you try that x = .4 t where t is in increments of days?

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