# Evaluate 2 integrals using method of circulation form and Green's theorem

$F=\langle 2y,-2x\rangle$ Where $R$ is bounded by $y=\sin x$ and $y=0$ for $0\le x\le \pi$.

I get the Green's theorem that the value is $-4 \times \text{area}$, but I have trouble finding the area of it. A to use normal integral i have trouble how to set it up.

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Do you think we're clairvoyant? How are we supposed to know what $F$ and $R$ are and which integrals you're trying to evaluate? –  joriki Dec 4 '12 at 2:09
F is a vector field, R is a region bounded by. And I suppose to make integrals from that vector field and bounds. –  Jack F Dec 4 '12 at 4:19
a) Please fix the question itself; people shouldn't have to read the comments to understand the question. b) What sort of integrals are you suppoed to make? Over the region, over the boundary, along the boundary, normal to the boundary? Why don't you just write out the integral instead of making us guess? If you don't understand the problem well enough to paraphrase it, just copy it verbatim. –  joriki Dec 4 '12 at 8:02