15.5.63 - Rewrite triple integral in spherical coordinates

In summary, the conversation discusses integrating in spherical coordinates for a given region and function, and determining the coefficients in a polynomial equation.
  • #1
karush
Gold Member
MHB
3,269
5
Write interated integrals in spherical coordinates
for the following region in the orders
$dp \, d\theta \, d\phi$
and
$d\theta \, dp \, d\phi$
Sketch the region of integration. Assume that $f$ is continuous on the region
\begin{align*}\displaystyle
I_{63}&=\int_{0}^{2\pi}\int_{\pi/6}^{\pi/2}\int_{2\csc{\phi}}^{4}
f(\rho,\phi,\theta)\rho^2
\,d\rho \,d\phi \,d\theta\\
\end{align*}
The standard equation of Sphere is:

\begin{align*}\displaystyle
f(\rho,\phi,\theta)
&=(\rho - \rho_0)^2 + (\phi - \phi_0)^2 + (\theta - \theta_0)^2 = \alpha ^2
\end{align*}

ok kinda ? what the $\rho^2$ would do to this

ok assume the new iterated sets would be according to d? set.

this was the pick for the graph I just picked bView attachment 7314
 
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  • #2
Re: 15.5.63 triple int of f(\rho,\phi,\theta)\ph^2

You appear to be confusing the equation of a sphere in Cartesian coordinates, [tex]x^2+ y^2+ z^2= r^2[/tex], with the equation of a sphere in spherical coordinates, [tex]\rho= r[/tex].
 
  • #3
Re: 15.5.63 triple int of f(\rho,\phi,\theta)\ph^2

\begin{align}\displaystyle
f_{12}&=(4s^2-as+5bs)+cs^2-d\\
&=40s^3+5s^2+s-20\\
&=-s^2-as+5bs+cs^2-40s^3-s-d=-20 \\
(s&=0) d=20\\
(s&=-1) -1+a-5b+c+40+1=0 \\
&a-5b+c=-40\\
(s&=1)-1+a+5b+c-40-1=0\\
&-a+5b+c =42\\
\therefore &c=2 \,b=8 \, a=1
\end{align}
 

FAQ: 15.5.63 - Rewrite triple integral in spherical coordinates

What are spherical coordinates used for in triple integrals?

Spherical coordinates are used to calculate triple integrals for objects with spherical symmetry, such as spheres or cones. They provide a convenient way to integrate over a three-dimensional region by using a radial distance, an azimuthal angle, and a polar angle.

How do I convert from Cartesian coordinates to spherical coordinates?

To convert from Cartesian coordinates (x, y, z) to spherical coordinates (ρ, θ, φ), use the following equations:

ρ = √(x^2 + y^2 + z^2)

θ = arctan(y/x)

φ = arccos(z/ρ)

Why is it important to use spherical coordinates in certain integrals?

In certain integrals, such as those involving objects with spherical symmetry, using spherical coordinates can greatly simplify the calculation. It allows for the integration limits to be set more easily and can result in simpler integrands.

What are the limitations of using spherical coordinates in triple integrals?

Spherical coordinates are not suitable for integrals that involve objects with non-spherical shapes. They also have limitations when attempting to integrate over non-continuous regions or regions with discontinuities.

Are there any tips for setting up and solving a triple integral using spherical coordinates?

One tip is to draw a diagram of the region of integration and label the coordinates to get a better understanding of the problem. It is also important to carefully consider the integration limits for each coordinate. Additionally, it may be helpful to use symmetry and trigonometric identities to simplify the integrand before solving the integral.

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