ok, the quiz today.

Well. That was instructive.  The median score was 4/10.   This should be a big wake-up call for the exam next week.

1) You need to know what to do with a parameterized path.  Really.  You  need to know what one looks like, where it goes into a line integral and how it goes into the line integral (two different ways--into the functions as x&y, and into the dr as dr/dt dt).  You need to know the difference between the vector field and the path.

2) you  need to know the difference between the line integral of a scalar function along a curve (which are not very important) and the line integral of a vector field along a curve (which are very important).  In particular if you're doing section 13.2 stuff (like |dr/dt|) on a section 13.3 problem (where you need a dot product with dr/dt), you won't be happy.

3) You need to be able to use the gift given to you when a vector field is conservative. Otherwise something that's very nice, becomes something that's very mean.

4)  btw, when you have an line integral

this is NOT the same thing as an integral with respect to a radial coordinate r.  Your clue in this is the dot product.

5) Polar coordinates won't help you.

6) oh, and *please*, nobody ever tell me again that the following formulas are valid. (prepare to tell me why on Monday)