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Use spherical coordinates. Evaluate ∫∫∫_E zdv, where E lies between the spheres x^2+ y^2 + z^2 =25 and x^2 + y^2 + z^2 =36 in the first octant.

User SiCN
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1 Answer

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Final answer:

The integral of zdv over the region E bounded by two spheres in the first octant is evaluated using spherical coordinates. The radial distance varies from 5 to 6 and the angular coordinates vary from 0 to \(\pi/2\). After separation and integration, the final value simplifies to \(\frac{3}{2}(36\sqrt{36} - 25\sqrt{25})\).

Step-by-step explanation:

To evaluate the integral \(\int\int\int_E zdv\) in spherical coordinates where E lies between the spheres \(x^2+ y^2 + z^2 = 25\) and \(x^2 + y^2 + z^2 = 36\) in the first octant, we need to set the limits for the spherical coordinates: \(\rho, \theta, \phi\).

The region E is bounded by spheres of radii 5 and 6, so the radial coordinate \(\rho\) varies from 5 to 6. The first octant corresponds to angle limits of \(\theta\) from 0 to \(\pi/2\) and \(\phi\) from 0 to \(\pi/2\). The volume element in spherical coordinates is \(\rho^2 \sin(\phi) d\rho d\theta d\phi\). And since z = \rho \cos(\phi), the integral becomes:

\(\int_{0}^{\pi/2}\int_{0}^{\pi/2}\int_{5}^{6} (\rho^3 \cos(\phi) \sin(\phi)) d\rho d\theta d\phi\).

To solve this integral, we can separate it into the product of three integrals, one for each variable, and integrate each one independently.

User A Jakhar
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