Mathematical physics line/surface integral problem

In summary, to solve the problem of finding the length of the line integral squared on a surface defined by the vector equation r=r(u,v), we can use the fundamental theorem of line integrals and the equation dS=|dr/dt|dr to find the functions E, G, and F. These functions can then be used to solve the problem.
  • #1
flaxstrax
12
0

Homework Statement



i have to show that the length of line integral squared on surface (ds^2) , which has vectorequation r=r(u,v) (r here is a vector), can be given as ds^2=Edu^2+2Fdudv+Gdv^2 (Find functions E,G,F)

Homework Equations


I should use diferential dr=du(t)e1+dv(t)e2 (dr, e1 and e2 here are vectors )
ds=|dr/dt|dr (dr here is vector)
dS=dS/n (dS/n is a vector )

The Attempt at a Solution


I'm pretty much stuck at the beginning , i don't see how those relevant equations help me here ?
Probably i should do something with dS/n.
Sorry for bad english and possibly translation, point out mistakes so i can learn.
 
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  • #2




Thank you for your post. To solve this problem, we need to use the fundamental theorem of line integrals, which states that the line integral of a vector field F along a curve C is equal to the surface integral of the curl of F over any surface S bounded by C. In this case, our surface is defined by the vector equation r=r(u,v), where r is a vector and u and v are parameters. To find the functions E, G, and F, we need to find the components of the vector r and then use the fundamental theorem of line integrals to find the surface integral of the curl of r over the surface S.

To find the components of r, we can use the differential dr=du(t)e1+dv(t)e2, where e1 and e2 are unit vectors in the u and v directions, respectively. This will give us the components of r in terms of u and v. Then, we can use the surface integral of the curl of r to find the functions E, G, and F. The surface integral is given by dS=|dr/dt|dr, where dS is a vector and dr is the differential of the vector r. By substituting the components of r into this equation, we can solve for E, G, and F.

I hope this helps you to solve the problem. If you need further assistance, please let me know. Good luck with your research!
 

Related to Mathematical physics line/surface integral problem

1. What is a line/surface integral in mathematical physics?

A line/surface integral is a mathematical tool used in physics to calculate the total value of a function over a specific line or surface. It involves breaking down a line or surface into small segments and calculating the contribution of each segment to the total value of the function.

2. How is a line/surface integral different from a regular integral?

A regular integral calculates the area under a curve, whereas a line/surface integral calculates the value of a function along a line or over a surface. It is essentially an extension of the concept of a regular integral to higher dimensions.

3. What types of problems can be solved using line/surface integrals in mathematical physics?

Line/surface integrals are commonly used to solve problems related to electromagnetism, fluid dynamics, and heat transfer. They can also be used in other areas of physics such as quantum mechanics and general relativity.

4. How are line/surface integrals calculated?

Line/surface integrals are typically calculated using integration techniques such as the fundamental theorem of calculus or Green's theorem. In some cases, they can also be solved using numerical methods.

5. What are some real-life applications of line/surface integrals in mathematical physics?

Line/surface integrals have a wide range of applications in physics, engineering, and other fields. Some examples include calculating the work done by a force on an object, determining the flow rate of a fluid through a surface, and finding the electric field around a charged object.

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