Line Integral - Vector Calculus

In summary, the line integral for the function f(x,y) = (x² - 2xy)î + (y² - 2xy)j, between the points (-1,1) and (1,1) along the parabola y = x² has been calculated to be -14/15. There may have been an error in the integral, as the correct approach involves substituting y = x² and integrating with respect to both x and y.
  • #1
cristina89
29
0

Homework Statement


Calculate the line integral:
f(x,y) = (x² - 2xy)î + (y² - 2xy)j, between the points (-1,1) and (1,1) along the parabola y = x².
(resp: -14/15)


The attempt at a solution
I thought something like this: substitue y = x², and then integrate de f(x,y). And then evaluate from -1 to 1, but it didn't work, obviously. How should I start solving this? I think I didn't get the concept about this kind of exercise...
 
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  • #2
If it didn't work then you must have made an error in the integrall. What, exactly, did you do?

The integral of this will be [itex]\int (x^2 - 2xy)dx+ (y^2- 2xy)dy[//itex]. Did you remember to put dy in terms of x also?
 
  • #3
HallsofIvy said:
If it didn't work then you must have made an error in the integrall. What, exactly, did you do?

The integral of this will be [itex]\int (x^2 - 2xy)dx+ (y^2- 2xy)dy[//itex]. Did you remember to put dy in terms of x also?

Ahh, that's exactly what I was forgetting! Thank you!
 

FAQ: Line Integral - Vector Calculus

What is a line integral in vector calculus?

A line integral is a type of integral that is defined over a curve or a line in a vector field. It is used to calculate the total value of a vector field along a given path or curve.

What is the difference between a line integral and a regular integral?

The main difference between a line integral and a regular integral is that a line integral is calculated over a specific path in a vector field, while a regular integral is calculated over a specific interval of a function.

How is a line integral calculated?

A line integral is calculated by breaking the given path into smaller segments and approximating the value of the vector field at each segment. The sum of these approximations gives the total value of the line integral.

What is the significance of line integrals in vector calculus?

Line integrals are important in vector calculus as they allow us to calculate the work done by a force along a path, the circulation of a vector field, and the flux of a vector field through a closed curve.

Are line integrals only used in two-dimensional vector fields?

No, line integrals can also be used in three-dimensional vector fields. In this case, the path is a curve in three-dimensional space and the integral is calculated using the same principles as in two dimensions.

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