# Line integral

1. Dec 8, 2013

### iScience

(disregard the [5+5+5] in the question)

attempt:
dr=(et(cost)+(sint)et)$\hat{i}$ + (-et(sint)+(cost)et)$\hat{j}$

∫<3+2xy, x2-3y2>$\cdot$<et(cost)+(sint)et, -et(sint)+(cost)et>dt

..at which point i remembered i had to parametrize F in terms of t, but didn't know how to do

2. Dec 8, 2013

### Simon Bridge

you want to integrate only over those values of x and y that lie on the curve mapped out by r(t) ... so what determines if a point (x,y) is on r?

3. Dec 8, 2013

### iScience

to answer your question, it would be if curve C lies if the domain of F, i don't see how this would help me though, i'm trying to put the vector field in terms of t.

4. Dec 8, 2013

### iScience

i would have to put the curve that is in terms of t, into some function of x and y then, how?

5. Dec 8, 2013

### iScience

this was a stupid question. Sorry, i just figured it out...

6. Dec 8, 2013

Well done :)