Surface Integral Limits: Solving for u and v

In summary, the given problem involves finding the limits for a double integral with variables x, y, and z. The equations involve x = u, y = v, and z = 1 - u - v, as well as ∂r/∂u × ∂r/∂v = i + j + k and F dot N = u^2 + 3v^2. The task is to evaluate ∫∫(u^2 + 3v^2 )dudv using the given limits of 0 ≤ u ≤ 1 and 0 ≤ v ≤ 1 - u. The order of integration can be flipped, and the setup is similar to any other double integral problem.
  • #1
Woolyabyss
143
1

Homework Statement


Problem is in image uploaded

Homework Equations


n/a

The Attempt at a Solution


x = u, y = v and z = 1 - u - v

∂r/∂u × ∂r/∂v = i + j + k
F dot N = u^2 + 3v^2

∫∫(u^2 + 3v^2 )dudv

My problem is I'm not sure what I should take as the limits?
Should I flip around the order of integration (dvdu) and have v go from 0 to 1-u and have u go from 0 to 1?
 

Attachments

  • Surface Integral.jpg
    Surface Integral.jpg
    30.8 KB · Views: 359
Physics news on Phys.org
  • #2
Woolyabyss said:

Homework Statement


Problem is in image uploaded

Homework Equations


n/a

The Attempt at a Solution


x = u, y = v and z = 1 - u - v

∂r/∂u × ∂r/∂v = i + j + k
F dot N = u^2 + 3v^2

∫∫(u^2 + 3v^2 )dudv

My problem is I'm not sure what I should take as the limits?
Should I flip around the order of integration (dvdu) and have v go from 0 to 1-u and have u go from 0 to 1?

It doesn't matter which order you use for the integration. You have a triangle in the uv plane and you can do it either way. It isn't clear why your author changes the names of the variables from xy to uv instead of letting x and y just represent themselves. Set it up like you would any double integral.
 
  • #3
They have given you the limits in the problem, where they write ##D=\{(u,v)\ :\ 0\leq u\ ...##. Have you tried using those? What did you get?
 

Related to Surface Integral Limits: Solving for u and v

1. What is a surface integral?

A surface integral is a type of integral in multivariable calculus that involves integrating a function over a two-dimensional surface in three-dimensional space. It is used to calculate quantities such as surface area, mass, and flux.

2. What are the limits of a surface integral?

The limits of a surface integral are the boundaries of the surface over which the integral is being calculated. These boundaries can be defined by equations, points, or curves.

3. How do you determine the limits of a surface integral?

The limits of a surface integral can be determined by visualizing the surface and identifying the boundaries. Alternatively, they can be determined by solving for the intersections of the surface with coordinate planes or other surfaces.

4. What are the applications of surface integrals?

Surface integrals have many applications in physics, engineering, and other fields. They are used to calculate surface area, mass and center of mass of objects, flux of vector fields, and work done by a force on a surface.

5. What is the difference between a surface integral and a volume integral?

A surface integral is calculated over a two-dimensional surface, while a volume integral is calculated over a three-dimensional region. Surface integrals can be thought of as the summation of infinitely many infinitesimal areas, while volume integrals are the summation of infinitely many infinitesimal volumes.

Similar threads

Replies
5
Views
1K
  • Calculus and Beyond Homework Help
Replies
16
Views
1K
  • Calculus and Beyond Homework Help
Replies
3
Views
1K
  • Calculus and Beyond Homework Help
Replies
4
Views
844
  • Calculus and Beyond Homework Help
Replies
5
Views
1K
  • Calculus and Beyond Homework Help
Replies
3
Views
664
  • Calculus and Beyond Homework Help
Replies
1
Views
139
  • Calculus and Beyond Homework Help
Replies
21
Views
1K
  • Calculus and Beyond Homework Help
Replies
1
Views
1K
  • Calculus and Beyond Homework Help
Replies
1
Views
624
Back
Top