Hey,

I have a tutorial question that is starting to bug me.

I know the formula is:

A = $\displaystyle \frac{1}{2}\oint_{C}(x\,\mathrm{d}y + y\, \mathrm{d}x)$

I have the problem:

Using Green's theorem, find the area of the disc of radius a.

I have notes and a previous example, but unsure where to start, Do I use the fact that:

$\displaystyle x^2+y^2=r^2$ where r =1

cheers