Evaluate ∫Γxy2dx+xydy on Γ={(x,y)∈R2:y=x2,x∈[−1,1]} with orientation clockwise using Green theorem
So Γ is a parabola to use Green we have to close the curve, to do so we will add the line from (1,1) to (−1,1)
Then
γ1(t)=(−t,1),t∈[−1,1]
γ2(t)=(t,t2),t∈[−1,1]
∫wanted=∫γ1(t)∪γ2(t)−∫γ1(t)
But we must have one parameterization of 2 variables which is closed to use green?
maybe ϕ(r,θ)=(sintcost,sin2t−sint),t∈[−π,−2π] is the closed curve?
Answer
By green's theorem,
∫Mdx+Ndy=∬
No comments:
Post a Comment