Triple Integral - How to set up limits?

In summary, the question is about finding the limits of a region of integration and writing equivalent iterated integrals using different combinations of dz, dy, and dx. The student is having trouble with the order dy dz dx and asks for help in finding the limits for the z-x plane. After receiving a hint, the student is able to solve the problem.
  • #1
jazzhands1
2
0

Homework Statement



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Find the limits of this region of integration, and write all possible equivalent iterated integrals given combinations of dz, dy, and dx.

Homework Equations


none that are really 'equations'?

The Attempt at a Solution


In particular, I'm having trouble with the order dy dz dx, as in:
∫∫∫ dy dz dx

I can get -1 and -√z for the bottom and top limits of the first integral (∫ dy) but I'm having a harder time finding the limits for ∫∫ dz dx in the z-x plane. I get 0 and y^2 for the top and bottom limits of that ∫dz, which shouldn't be right since it both should be functions of (x) and not of (y).

I'd appreciate a pointer or hint. Thanks!
 
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  • #2
First thing you note is that x is completely independent of y and z.

Let's then say y can be anywhere between zero and one. Which values of z are allowed for each y? This gives you the limits for the z-integral.
 
  • #3
Got it, thanks a bunch! =)
 

FAQ: Triple Integral - How to set up limits?

1. What is a triple integral and how is it different from a regular integral?

A triple integral is a mathematical tool used to calculate the volume of a three-dimensional shape. It is different from a regular integral in that it involves integrating over three variables, rather than just one. This allows us to calculate the volume of more complex shapes that cannot be easily calculated with a regular integral.

2. How do you set up the limits for a triple integral?

The limits for a triple integral are determined by the three variables being integrated over. The outermost integral will have the limits for the first variable, the middle integral will have the limits for the second variable, and the innermost integral will have the limits for the third variable. These limits are typically based on the boundaries of the shape being integrated over.

3. Can the order of integration be changed for a triple integral?

Yes, the order of integration can be changed for a triple integral. This is known as changing the order of integration or rearranging the integral. However, the limits of integration must also be changed to match the new order. In some cases, changing the order of integration can make the integral easier to solve.

4. What types of shapes can be integrated using a triple integral?

A triple integral can be used to integrate over any three-dimensional shape, including spheres, cones, cylinders, and more complex shapes such as tori or ellipsoids. The shape must have well-defined boundaries in order for the limits of integration to be determined.

5. How is a triple integral used in real-world applications?

A triple integral has many practical applications in fields such as physics, engineering, and economics. It can be used to calculate the volume of a 3D object, the mass of a solid with varying density, the moment of inertia of a rotating object, and the center of mass of an irregularly shaped object, to name a few examples.

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