Ask your own question, for FREE!
Mathematics 16 Online
OpenStudy (anonymous):

How to find the closed path when using Stoke's theorem from points given?

OpenStudy (anonymous):

For example: (0,0,0) to (2,0,0) to (0,2,1) to (0,0,0)

OpenStudy (anonymous):

At Z = y/2

OpenStudy (anonymous):

The easiest thing to do is parameterize the path like this: If you're going from point \(\vec{a}\) to point \(\vec{b}\), then \[ \vec{r}(t) = \vec a + t\cdot \left(\vec{b} - \vec{a} \right) \] where t runs from zero to one. For example, along the first segment, \[\vec{r}(t) = <0,0,0> + t\cdot<2,0,0>= <2t,0,0> \] You can see that at t=0 you're at point \(\vec a\) and at t=1 you're at point \(\vec b\).

OpenStudy (anonymous):

Right and at those points they would help me to determine the limits of integration of a function?

OpenStudy (anonymous):

\[\int\limits_{C}^{} F dr = \int\limits_{}^{} _S \int\limits_{}^{} (Curl F) Nds\]

OpenStudy (anonymous):

Remember that \[\oint \vec f \cdot d\vec r = \int_1 \vec f \cdot d\vec{r}_1 + \int_2 \vec f \cdot \vec{r}_2 + \int_3 \vec f \cdot d\vec r_3 \] So you need to break the integral up into three integrals, one along each segment. If you parameterize like I did, then each one of those integrals will become an integral over the variable t, which will run from 0 to 1 each time.

OpenStudy (anonymous):

And how would the Z = y/2 come into play?

OpenStudy (anonymous):

That does not make sense in the context of the question.

OpenStudy (anonymous):

I have a vector \[F(x,y,z) = -3y^2 i + 4z j +6xk\] I found the curl to be: <-4, -6, 6y >

OpenStudy (anonymous):

to place it into stokes theorem I was given that triangular path which lies in the plane Z =y/2

ganeshie8 (ganeshie8):

choose ur surface and find its normal vector

OpenStudy (anonymous):

What do you mean by choosing my surface?

ganeshie8 (ganeshie8):

|dw:1416886686540:dw|

OpenStudy (anonymous):

|dw:1416886726182:dw| projected onto the x-z plane

ganeshie8 (ganeshie8):

choose your surface as the plane passing containing the path

OpenStudy (anonymous):

Not sure how you got the dS?

ganeshie8 (ganeshie8):

never seen that before ?

OpenStudy (anonymous):

oh right the -g_x (x,y) and - g_y (x,y)

ganeshie8 (ganeshie8):

yes dot that with curl and setup the double integral xy plane

ganeshie8 (ganeshie8):

sorry the earlier formila is for ndS : z = f(x,y) ndS = <-f_x, -f_y, 1>dxdy

ganeshie8 (ganeshie8):

z = f(x,y) = y/2 ndS = <0, -1/2, 1> dxdy right ?

OpenStudy (anonymous):

|dw:1416887008288:dw|

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!