Calculate the line integral on the negatively oriented unit circumference (like the hands of the clock) under...











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Calculate the line integral on the negatively oriented unit circumference (like the hands of the clock) under the $F(x,y)=(e^x+x^2y,e^y-xy^2)$ field



I have thought to do the following to solve this:



$int_{C'}Fcdot dr=int_{-C}Fcdot dr=-int_CFcdot dr$, where $C$ is a positively oriented curve.



But $int_CFcdot dr=intint_D(frac{partial Q}{partial x}-frac{partial P}{partial y})dA=intint_D(-y^2-x^2)dA=-intint_D(x^2+y^2)dA=-int_{0}^{2pi}int_{0}^{1}r^3drdtheta=-int_{0}^{2pi}1/4dtheta=-2pi/4=-pi/2$.



Then $int_{C'}Fcdot dr=pi/2$



Is this fine? Thank you.










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  • How do you include the positively oriented condition?
    – Rafa Budría
    Nov 17 at 8:46










  • Pues, cambio la curva por la misma pero orientada positivamente, esto sí se puede hacer así?
    – user402543
    Nov 17 at 19:56










  • Ah, yes, I didn't see that. Sorry.
    – Rafa Budría
    Nov 17 at 20:15















up vote
0
down vote

favorite
1












Calculate the line integral on the negatively oriented unit circumference (like the hands of the clock) under the $F(x,y)=(e^x+x^2y,e^y-xy^2)$ field



I have thought to do the following to solve this:



$int_{C'}Fcdot dr=int_{-C}Fcdot dr=-int_CFcdot dr$, where $C$ is a positively oriented curve.



But $int_CFcdot dr=intint_D(frac{partial Q}{partial x}-frac{partial P}{partial y})dA=intint_D(-y^2-x^2)dA=-intint_D(x^2+y^2)dA=-int_{0}^{2pi}int_{0}^{1}r^3drdtheta=-int_{0}^{2pi}1/4dtheta=-2pi/4=-pi/2$.



Then $int_{C'}Fcdot dr=pi/2$



Is this fine? Thank you.










share|cite|improve this question
























  • How do you include the positively oriented condition?
    – Rafa Budría
    Nov 17 at 8:46










  • Pues, cambio la curva por la misma pero orientada positivamente, esto sí se puede hacer así?
    – user402543
    Nov 17 at 19:56










  • Ah, yes, I didn't see that. Sorry.
    – Rafa Budría
    Nov 17 at 20:15













up vote
0
down vote

favorite
1









up vote
0
down vote

favorite
1






1





Calculate the line integral on the negatively oriented unit circumference (like the hands of the clock) under the $F(x,y)=(e^x+x^2y,e^y-xy^2)$ field



I have thought to do the following to solve this:



$int_{C'}Fcdot dr=int_{-C}Fcdot dr=-int_CFcdot dr$, where $C$ is a positively oriented curve.



But $int_CFcdot dr=intint_D(frac{partial Q}{partial x}-frac{partial P}{partial y})dA=intint_D(-y^2-x^2)dA=-intint_D(x^2+y^2)dA=-int_{0}^{2pi}int_{0}^{1}r^3drdtheta=-int_{0}^{2pi}1/4dtheta=-2pi/4=-pi/2$.



Then $int_{C'}Fcdot dr=pi/2$



Is this fine? Thank you.










share|cite|improve this question















Calculate the line integral on the negatively oriented unit circumference (like the hands of the clock) under the $F(x,y)=(e^x+x^2y,e^y-xy^2)$ field



I have thought to do the following to solve this:



$int_{C'}Fcdot dr=int_{-C}Fcdot dr=-int_CFcdot dr$, where $C$ is a positively oriented curve.



But $int_CFcdot dr=intint_D(frac{partial Q}{partial x}-frac{partial P}{partial y})dA=intint_D(-y^2-x^2)dA=-intint_D(x^2+y^2)dA=-int_{0}^{2pi}int_{0}^{1}r^3drdtheta=-int_{0}^{2pi}1/4dtheta=-2pi/4=-pi/2$.



Then $int_{C'}Fcdot dr=pi/2$



Is this fine? Thank you.







calculus integration multivariable-calculus greens-theorem






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edited Nov 16 at 22:38

























asked Nov 16 at 19:10









user402543

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  • How do you include the positively oriented condition?
    – Rafa Budría
    Nov 17 at 8:46










  • Pues, cambio la curva por la misma pero orientada positivamente, esto sí se puede hacer así?
    – user402543
    Nov 17 at 19:56










  • Ah, yes, I didn't see that. Sorry.
    – Rafa Budría
    Nov 17 at 20:15


















  • How do you include the positively oriented condition?
    – Rafa Budría
    Nov 17 at 8:46










  • Pues, cambio la curva por la misma pero orientada positivamente, esto sí se puede hacer así?
    – user402543
    Nov 17 at 19:56










  • Ah, yes, I didn't see that. Sorry.
    – Rafa Budría
    Nov 17 at 20:15
















How do you include the positively oriented condition?
– Rafa Budría
Nov 17 at 8:46




How do you include the positively oriented condition?
– Rafa Budría
Nov 17 at 8:46












Pues, cambio la curva por la misma pero orientada positivamente, esto sí se puede hacer así?
– user402543
Nov 17 at 19:56




Pues, cambio la curva por la misma pero orientada positivamente, esto sí se puede hacer así?
– user402543
Nov 17 at 19:56












Ah, yes, I didn't see that. Sorry.
– Rafa Budría
Nov 17 at 20:15




Ah, yes, I didn't see that. Sorry.
– Rafa Budría
Nov 17 at 20:15















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