Using Green's Theorem, I'm trying to calculate the line integral of F*dr where C is the unit circle (counterclockwise) and F(x,y)=6yi+4xyj. I've posted a screenshot of my first two tries.

Question

anonymous · Answer

attachment

ganeshie8 · Answer

there is a mistake in the start, the integrand is wrong

ganeshie8 · Answer

it should be  $\large 4y \color{Red}{-}6$  right ?

anonymous · Answer

Ha! That's about 4 pixels of pure d'oh! :)

ganeshie8 · Answer

use wolfram to double check ur answers

ganeshie8 · Answer

here it is http://www.wolframalpha.com/input/?i=%5Cint_0%5E%7B2%5Cpi%7D%5Cint_0%5E1+%284r%5Csin%5Ctheta+-+6%29*r+drd%5Ctheta

anonymous · Answer

Funny thing is, I have a copy of Mathematica, but we' re not even allowed calculators in the exams.

ganeshie8 · Answer

use calculator to double check ur answer, not as replacement for your head ;)

anonymous · Answer

Fair enough. I've been a programmer for the last 15 years, so it's been a little bit of an adjustment to not let the machine do the work. Thanks for your help! :D

ganeshie8 · Answer

these things must be super easy for you once you know how they work !

anonymous · Answer

I wouldn't say *super* easy, but I'm sure it gives me an advantage. The code I've written for Web content management systems is certainly more complex than anything I've experienced in calculus so far. The difference is, no one asks you at work to dump all of your functions on paper from memory and calculate them by hand.