Multivariable Calculus HELP!

[cheertink]

I need some help! Can anyone figure this problem out for me?

Let C be the positively oriented circle x^2+y^2=1. Use Green's Theorem to evaluate the line integral 7ydx+14xdy

Thanks!!

 

[galactus]

You have a circle of radius 1.

\(\displaystyle \frac{\partial}{\partial(x)}14x-\frac{\partial}{\partial(y)}7y\)

\(\displaystyle 14-7=7\)

\(\displaystyle 7{\int_0^{2{\pi}}{\int_0^{1}}rdrd{\theta}\)

\(\displaystyle =7{\pi}\)