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Active Calculus - Multivariable

Activity 12.7.3.
In this activity, we will use spherical coordinates to help us more easily understand some natural geometric objects.
(a)
Recall that the sphere of radius \(a\) has spherical equation \(\rho = a\text{.}\) Set up and evaluate an iterated integral in spherical coordinates to determine the volume of a sphere of radius \(a\text{.}\)
(b)
Set up, but do not evaluate, an iterated integral expression in spherical coordinates whose value is the mass of the solid obtained by removing the cone \(\phi=\frac{\pi}{4}\) from the sphere \(\rho = 2\) if the density \(\delta\) at the point \((x,y,z)\) is \(\delta(x,y,z) = \sqrt{x^2+y^2+z^2}\text{.}\) An illustration of the solid is shown in Figure 12.7.7.
Figure 12.7.7. The solid cut from the sphere \(\rho = 2\) by the cone \(\phi=\frac{\pi}{4}\)