Using Green's Theorem to evaluate the line integral.

In summary, the conversation is about using Green's Theorem to evaluate a line integral with given bounds and path. The solution involves dividing the triangle into two pieces and setting the upper and lower limits for x and y accordingly. The conversation also clarifies the reasoning behind the chosen bounds and the understanding of the process.
  • #1
Unart
27
0

Homework Statement



Green's Theorem to evaluate the line following line integral, oriented clockwise.
∫xydx+(x^2+x)dy, where C is the path though points (-1,0);(1,0);(0,1)

Homework Equations


Geen's theorem: [itex]∫F°DS=∫∫ \frac{F_2}{δx}-\frac{F_1}{δy}[/itex]


The Attempt at a Solution


attachment.php?attachmentid=53123&stc=1&d=1353355503.jpg


What would I use for the bounds. I know it has to do with the triangle. But how would I find the bounds?
 

Attachments

  • photo.jpg
    photo.jpg
    29 KB · Views: 507
Physics news on Phys.org
  • #2
You've pretty much written it down yourself: the lower limit is clearly y= 0. The upper limits are those two other sides of the triangle: if x< 0, y= x+ 1, if x> 0, y= -x+1.
So you can divide this into two sets of integrals: for x from -1 to 1, y goes from 0 to x+ 1, for x from 0 to 1, y goes from 0 to 1- x.
 
  • #3
Thanks... Halls. I wasn't sure what to do, but I understand now. It's like you've divided the triangle into 2 pieces.
 
  • #4
And made both of the equations x+1 and 1-x satisfy their respective points... but I think the upper and lower bound of x+1 is -1 and 0 respectively since it goes from 0 to satisfy point (0,1) and -1 for (-1,0) and goes from the first point to the other.
 

1. What is Green's Theorem?

Green's Theorem is a mathematical theorem that relates the line integral around a simple closed curve in the plane to a double integral over the region enclosed by the curve. It is named after mathematician George Green and is a fundamental tool in vector calculus.

2. How is Green's Theorem used to evaluate a line integral?

To use Green's Theorem to evaluate a line integral, the region enclosed by the curve must be divided into smaller regions and the double integral is calculated for each of these regions. Then, the sum of these double integrals is equal to the line integral around the original curve.

3. What are the advantages of using Green's Theorem to evaluate a line integral?

Green's Theorem can make the evaluation of line integrals simpler and more efficient, especially for curved and irregular regions. It also allows for the use of techniques from double integrals, which may be more familiar to some mathematicians.

4. Are there any limitations to using Green's Theorem?

Green's Theorem can only be applied to simple closed curves, which means that the curve cannot intersect itself or have any holes. It also requires the region to be divided into smaller regions, which can be time-consuming for complex curves.

5. Can Green's Theorem be used in higher dimensions?

No, Green's Theorem is only applicable in two dimensions. However, there are similar theorems such as Stokes' Theorem and the Divergence Theorem that can be used in three dimensions to evaluate line integrals.

Similar threads

  • Calculus and Beyond Homework Help
Replies
3
Views
271
  • Calculus and Beyond Homework Help
Replies
12
Views
989
  • Calculus and Beyond Homework Help
Replies
10
Views
439
  • Calculus and Beyond Homework Help
Replies
3
Views
1K
  • Calculus and Beyond Homework Help
Replies
12
Views
2K
  • Calculus and Beyond Homework Help
Replies
4
Views
1K
  • Calculus and Beyond Homework Help
Replies
6
Views
2K
  • Calculus and Beyond Homework Help
Replies
2
Views
1K
  • Calculus and Beyond Homework Help
Replies
11
Views
1K
  • Calculus and Beyond Homework Help
Replies
4
Views
1K
Back
Top