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Active Calculus - Multivariable

Activity 12.7.2.
In this activity, we will work with a few triple integrals and look at the advantages of utilizing cylindrical coordinates for the iterated integral calculation.
(a)
Let \(S\) be the solid bounded above by the graph of \(z = x^2+y^2\) and below by \(z=0\) on the unit disk in the \(xy\)-plane.
(a)
The projection of the solid \(S\) onto the \(xy\)-plane is a disk. Describe this disk using inequalities in polar coordinates.
(b)
Use your inequalities from above to write inequalities in cylindrical coordinates that describe the solid \(S\text{.}\)
(c)
Write out a set of iterated integrals that will evaluate to the volume of \(S\text{.}\) You do not need to evaluate this integral.
(b)
Suppose the density of the cone defined by \(r = 1 - z\text{,}\) with \(z \geq 0\text{,}\) is given by \(\delta(r, \theta, z) = z\text{.}\) A picture of the cone is shown at in Figure 12.7.2. Set up an iterated integral in cylindrical coordinates that gives the mass of the cone. You do not need to evaluate this integral.
Figure 12.7.2. The cylindrical cone \(r = 1-z\)
(c)
Write an iterated integral expression in cylindrical coordinates whose value is the volume of the solid bounded below by the cone \(z = \sqrt{x^2+y^2}\) and above by the cone \(z = 4 - \sqrt{x^2+y^2}\text{.}\) A picture is shown in Figure 12.7.3. You do not need to evaluate this integral.
Figure 12.7.3.