Converting a triple integral from spherical to cartesian, cylindrical coordinates

In summary: Help.more pertinent questions to you are:What have you tried?Where are you stuck?according to the rules for Homework help on this forum, you need to show your attempt at working the problem and/or give indication of making a serious effort at understanding the problem
  • #1
bfusco
128
1

Homework Statement


Consider the interated integral I=∫∫∫ρ^3 sin^2(∅) dρ d∅ dθ
-the bounds of the first integral (from left to right) are from 0 to pi
-the bounds of the second integral are from 0 to pi/2
-the bounds of the third integral are from 1 to 3

a)express I as an interated integral in terms of the cartesian coordinates x,y,z.
b)express I as an interated integral in terms of the cylindrical coordinates r, θ, z

Homework Equations


This is on a practice final i have soon so i would appreciate it if the aid given to me isn't spread across a few days. thank you in advance
 
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  • #2
bfusco said:

Homework Statement


Consider the interated integral I=∫∫∫ρ^3 sin^2(∅) dρ d∅ dθ
-the bounds of the first integral (from left to right) are from 0 to pi
-the bounds of the second integral are from 0 to pi/2
-the bounds of the third integral are from 1 to 3

a)express I as an interated integral in terms of the cartesian coordinates x,y,z.
b)express I as an interated integral in terms of the cylindrical coordinates r, θ, z

Homework Equations


This is on a practice final i have soon so i would appreciate it if the aid given to me isn't spread across a few days. thank you in advance

Do you mean right to left? Start by drawing, or at least describing the object, then we can talk.
 
  • #3
its pretty clear, as there are 3 integral signs, the left most integral has bounds 0 to pi, so on and so forth. this is the question as given to me on my practice final there is nothing more i can give you to describe the function.
 
  • #4
bfusco said:
its pretty clear, as there are 3 integral signs, the left most integral has bounds 0 to pi, so on and so forth. this is the question as given to me on my practice final there is nothing more i can give you to describe the function.

My question about your limits would have been prevented by you using latex and putting the limits on the integrals. But putting that aside, what you have to do is use the limits to draw a picture of the object. That's the only way to figure out what the figure looks like and get the appropriate limits in the other coordinate systems.
 
  • #5
bfusco said:
its pretty clear, as there are 3 integral signs, the left most integral has bounds 0 to pi, so on and so forth. this is the question as given to me on my practice final there is nothing more i can give you to describe the function.
LCKurtz was simply trying to help you out. How about saying: from outside to inside or from inside to outside ?

More pertinent questions to you are:
What have you tried?

Where are you stuck?​
According to the rules for Homework help on this Forum, You need to show your attempt at working the problem and/or give indication of making a serious effort at understanding the problem .
 
  • #6
lol i love when people recite what the rules of the forum are, i know he was only trying to help me but i didnt understand his response, i didnt feel like continuing so i went somewhere else with a slightly different question. had i had anything to give as far as my attempt at a solution i would have posted one, so there is no need for someone to attempt to take the "mature" person standpoint and imply that i have done something wrong. how are you suppose to put an attempt at the solution if you don't know where to start. so don't go reciting rules as if they arent already understood.

i needed help and i felt that my aid would have been more appropriate had i asked the questions in the steps recommended by my professor, i.e graph the function, determine the bounds, rewrite the equation, and so on. the only problem is i don't know anything about spherical coordinates so i thought a more appropriate place to start was from where i worded my other post.
 
  • #7
bfusco said:
the only problem is i don't know anything about spherical coordinates

This forum section's purpose is explicitly labelled as "homework help" and not "teaching calculus for dummies". You will obviously not be able to do any questions if you do not understand the subject matter in the first place.

What you need is a proper introduction to the topic before attempting any questions. Read and learn from your notes or get a good book. You must at least form an idea of what spherical coordinates is all about. Familiarize yourself with the concepts and formulas. Study the examples in your notes/book. Then, look again at your question. At that point, if you still can't solve it, you'll be in a much better position to appreciate our help.
 
  • #8
bfusco said:
lol i love when people recite what the rules of the forum are, i know he was only trying to help me but i didnt understand his response, i didnt feel like continuing so i went somewhere else with a slightly different question. had i had anything to give as far as my attempt at a solution i would have posted one, so there is no need for someone to attempt to take the "mature" person standpoint and imply that i have done something wrong. how are you suppose to put an attempt at the solution if you don't know where to start. so don't go reciting rules as if they arent already understood.

i needed help and i felt that my aid would have been more appropriate had i asked the questions in the steps recommended by my professor, i.e graph the function, determine the bounds, rewrite the equation, and so on. the only problem is i don't know anything about spherical coordinates so i thought a more appropriate place to start was from where i worded my other post.

Check your PMs.
 

Related to Converting a triple integral from spherical to cartesian, cylindrical coordinates

What is the purpose of converting a triple integral from spherical to cartesian or cylindrical coordinates?

Converting a triple integral from spherical to cartesian or cylindrical coordinates allows for easier integration and calculation of volumes in three-dimensional space. It also provides a different perspective for analyzing and solving problems.

What are the main differences between spherical, cartesian, and cylindrical coordinates?

Spherical coordinates use a radius, polar angle, and azimuthal angle to describe a point in three-dimensional space. Cartesian coordinates use three perpendicular axes (x, y, and z) to describe a point, while cylindrical coordinates use a radius, angle, and height to define a point.

How do I convert a triple integral from spherical to cartesian coordinates?

To convert from spherical to cartesian coordinates, you can use the following equations:
x = ρsinφcosθ
y = ρsinφsinθ
z = ρcosφ, where ρ is the radius, φ is the polar angle, and θ is the azimuthal angle. These equations can then be used to transform the limits of integration and the integrand in the triple integral.

What are the advantages of using cylindrical coordinates over spherical coordinates?

Cylindrical coordinates can be more convenient to use when dealing with problems that involve circular or cylindrical symmetry, such as calculating the volume of a cylinder or finding the center of mass of a circular disk. In these cases, cylindrical coordinates can simplify the integration process.

Are there any drawbacks to converting a triple integral from spherical to cartesian coordinates?

One potential drawback is that the conversion process may be more complicated and involve more steps compared to using a single coordinate system. Additionally, the limits of integration may become more complex, making the integration process more challenging.

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