Cartersian double integral converted to polar and then evaluated #2

In summary, Cartesian double integral converted to polar is a useful method for evaluating integrals over regions with circular or radial symmetry. It involves converting the integrand and limits of integration to polar form and using known techniques for polar integrals. However, not all double integrals can be converted to polar and there are limitations such as increased complexity and difficulty in determining limits of integration. This method is only applicable for 2-dimensional integrals.
  • #1
jimbo71
81
0

Homework Statement


convert line one to polar integral and then evaluate
see problems 16 attachement


Homework Equations


r^2=y^2+x^2



The Attempt at a Solution


I changed to polar and evaluated the double integral but I come up with an answer of negative pi which seems odd since it is an area value and should be posititve. What did i do wrong?
see problem 16 attachement
 

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  • #2
You made a careless sign error at the start of the 4th line. There should be a negative in front of the integral in that step.
 

1. What is Cartersian double integral converted to polar and how is it evaluated?

Cartersian double integral converted to polar is a method used to evaluate integrals over regions that are more easily defined in polar coordinates. It involves converting the integrand and limits of integration from Cartesian to polar form. The integral is then evaluated using known techniques for polar integrals.

2. Why is it useful to convert a double integral from Cartesian to polar?

Converting a double integral from Cartesian to polar can simplify the integrand and limits of integration, making it easier to evaluate the integral. It is especially useful for integrating over regions with circular or radial symmetry.

3. How do you convert a Cartesian double integral to polar?

To convert a Cartesian double integral to polar, use the following substitutions:
x = r cos(θ)
y = r sin(θ)
dx dy = r dr dθ
The limits of integration should also be adjusted accordingly.

4. Can any double integral be converted to polar?

No, not all double integrals can be converted to polar. The integral must have some form of circular or radial symmetry for the conversion to be useful. Additionally, the region of integration must be more easily defined in polar coordinates.

5. Are there any limitations to using the conversion method for evaluating double integrals?

One limitation is that the conversion from Cartesian to polar can sometimes make the integral more complex. It may also be difficult to determine the limits of integration in polar form for certain regions. Additionally, this method is only applicable for 2-dimensional integrals and cannot be used for higher dimensions.

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