Line Integral Homework: Find Curve & Vector Field for Green's Theorem [Solved]

In summary: This way, the integral will still be equal by Green's Theorem, but the vector field will be different. In summary, there are infinitely many possible vector fields that satisfy the given conditions.
  • #1
mottov2
13
0

Homework Statement


Find the parameterized curve gamma and vector field F so that
the [itex]\int[/itex][itex]\gamma[/itex] F ds = [itex]\int[/itex][itex]\int2xy dx dy[/itex] by Green's Theorem.
where -2<y<2
1-sqrt(4-y2) < x < 1+sqrt(4-y2)

The Attempt at a Solution

x = 1 + sqrt(4-y2)
(x-1)2=4-y2
(x-1)2+y2=4

so the path is a circle centered at (1,0) with radius of 2.
parametrize this by setting x = 1+2Cos(t) and y = 2Sin(t)

for the vector field I got F = (xy2,2x2y)
but is there more than one possible vector field?
 
Physics news on Phys.org
  • #2
mottov2 said:

Homework Statement


Find the parameterized curve gamma and vector field F so that
the [itex]\int[/itex][itex]\gamma[/itex] F ds = [itex]\int[/itex][itex]\int2xy dx dy[/itex] by Green's Theorem.
where -2<y<2
1-sqrt(4-y2) < x < 1+sqrt(4-y2)

The Attempt at a Solution




x = 1 + sqrt(4-y2)
(x-1)2=4-y2
(x-1)2+y2=4

so the path is a circle centered at (1,0) with radius of 2.
parametrize this by setting x = 1+2Cos(t) and y = 2Sin(t)

for the vector field I got F = (xy2,2x2y)
but is there more than one possible vector field?

Yes, there are infinitely many such vector fields. For example, you can modify yours like this:$$
\vec F = \langle xy^2+g(x), 2x^2y+h(y)\rangle$$where h and g can be any differentiable functions.
 

1. What is a line integral?

A line integral is a type of integral in multivariable calculus that calculates the total value of a function along a given curve. It takes into account both the magnitude and direction of the curve, and is often used to find work, flux, or circulation in physics and engineering problems.

2. How do I find the curve for Green's Theorem?

To find the curve for Green's Theorem, you first need to determine the region over which the integral will be calculated. Then, choose an appropriate parametrization for the curve that forms the boundary of this region. This could be a line, circle, or other curve. Finally, plug this parametrization into the integral formula for Green's Theorem.

3. What is a vector field?

A vector field is a mathematical concept that assigns a vector to each point in a given space. These vectors represent the direction and magnitude of a particular physical quantity, such as velocity or force, at each point in the space. Vector fields are commonly used in physics to model and analyze various phenomena.

4. How do I solve a line integral using Green's Theorem?

To solve a line integral using Green's Theorem, you first need to find the curve and vector field for the given problem. Then, use the integral formula for Green's Theorem, which involves integrating the vector field over the curve. Finally, evaluate the resulting integral to find the desired value.

5. What are some real-world applications of Green's Theorem?

Green's Theorem has many real-world applications, particularly in physics and engineering. It is commonly used to calculate work done by a force, flux through a surface, and circulation of a fluid. It can also be applied in electromagnetism, fluid mechanics, and heat transfer problems.

Similar threads

  • Calculus and Beyond Homework Help
Replies
3
Views
237
  • Calculus and Beyond Homework Help
Replies
12
Views
976
  • Calculus and Beyond Homework Help
Replies
10
Views
411
  • Calculus and Beyond Homework Help
Replies
2
Views
231
  • Calculus and Beyond Homework Help
Replies
8
Views
865
  • Calculus and Beyond Homework Help
Replies
2
Views
360
  • Calculus and Beyond Homework Help
Replies
12
Views
2K
  • Calculus and Beyond Homework Help
Replies
2
Views
1K
  • Calculus and Beyond Homework Help
Replies
20
Views
442
  • Calculus and Beyond Homework Help
Replies
6
Views
2K
Back
Top