# Another disagreement with course Line integral homework

1. Apr 3, 2012

### 1MileCrash

1. The problem statement, all variables and given/known data

http://img39.imageshack.us/img39/6669/wileyplus.png [Broken]

The field is conservative.

With their description of C, and using the Fundamental Theorem of Calculus for Line Integrals, would you evaluate

f(11/sqrt(2), 11/sqrt(2)) - f(0,0)

or

f(11/sqrt(2), 11/sqrt(2)) - f(11,0)

?

Their description of C, to me, is that we start at the origin and end at (11/sqrt(2), 11/sqrt(2)).

However, their "show solution" shows them doing:

f(11/sqrt(2), 11/sqrt(2)) - f(11,0)

Either I don't understand, or wiley plus has been wrong for the dozenth time. FYI my answer looks so strange because I kept changing it up to get it to accept.

The whole point of path independence is that I don't give a crap about where the circle or whatever starts, the point (11,0) is completely irrelevant!

Last edited by a moderator: May 5, 2017
2. Apr 4, 2012

### ehild

It is not that simple. You have to integrate along a line from (0;0) to (11/√2;11/√2).

You can choose the path between (0;0) and (11/√2;11/√2) as you like. One easy choice is along the x axis from (0;0) to (11/√2;0), then vertically up from (11/√2;0) to (11/√2;11/√2).

ehild

Last edited by a moderator: May 5, 2017
3. Apr 4, 2012

### vela

Staff Emeritus
Wiley Plus is wrong. You're right.

4. Apr 4, 2012

### ehild

1MikeCrash,
yes, the solution in the gray box is correct. I did not realize that it was yours.

ehild