Verify Greens theorem half done

In summary: It would be y=x, right? Now, if you let x=t, then y=t as well because they are on the same line. Therefore, x=t and y=t form a parameterization for the line segment from (0,0) to (1,1).
  • #1
Jaqsan
17
0

Homework Statement



Verify Greens theorem for the line integral ∫c xydx + x^2 dy where C is the triangle with vertices (0,0) (1,1) (2,0). This means show both sides of the theorem are the same.


Homework Equations


∫c <P,Q> dr = ∫∫dQ/dx -dP/dy dA
∫c xydx + x^2dy

The Attempt at a Solution



Ok, I know the how to verify it with Greens Theorem. My answer comes out to be 1, I just can't figure out the steps to parametrize it or whatever I need to do to solve it without Greens Theorem.

I'm honestly stuck at the first step
∫<P,Q> dr = ∫<xy, x^2> dr
 
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  • #2
You have to break the contour up into three pieces. For example, the first leg might go from (0,0) to (1,1). The parameterization you could use would be x=t, y=t, where t runs from 0 to 1.
 
  • #3
How do I come up with the parameters x=t and y=t. There's no equation to get it from.
 
  • #4
You examine the piece of the contour under consideration. Remember, t is just a parameter. You are trying to find a relation using t which gives all of the (x,y) coordinates on a straight line segment starting with the point (0,0) and ending at the point (1,1). [Hint: you get to use your imagination. There may be more than one parameterization.]
 
  • #5
For the given contour, the points (0,0) and (1,1) are connected by a line segment, right? So what would the equation of that line be?
 

1. What is Green's theorem and what is its purpose?

Green's theorem is a mathematical tool used in vector calculus to evaluate a line integral over a closed curve by converting it into a double integral over the region enclosed by the curve. Its purpose is to simplify the calculation of line integrals by relating them to easier-to-evaluate double integrals.

2. How is Green's theorem verified?

To verify Green's theorem, you must first check that the region enclosed by the curve is simply connected (i.e. has no holes or disjoint parts). Then, calculate the line integral around the curve and the double integral over the region enclosed by the curve. If they are equal, Green's theorem is verified.

3. What is meant by "half done" in the context of verifying Green's theorem?

"Half done" refers to the fact that Green's theorem can only be applied to certain types of line integrals, specifically those that can be converted into double integrals over a simply connected region. If the line integral cannot be converted, or if the region is not simply connected, then Green's theorem cannot be used and the verification is considered "half done."

4. What are some applications of Green's theorem in science?

Green's theorem has many applications in science, particularly in physics and engineering. It is used to solve problems involving work and energy, fluid flow, electromagnetic fields, and more. It is also used in the study of vector fields, such as in the analysis of wind patterns or ocean currents.

5. Are there any limitations or exceptions to using Green's theorem?

Yes, there are some limitations and exceptions to using Green's theorem. As mentioned before, the region must be simply connected and the line integral must be convertible to a double integral. Additionally, Green's theorem only applies to two-dimensional vector fields. In three-dimensional spaces, a similar theorem called Stokes' theorem is used. There are also special cases, such as when the curve encloses a singularity or when the vector field is not continuous, where Green's theorem cannot be applied.

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