vector field: changing vector magnitudes to make it conservative











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Consider a vector field $$vec{F}(x,y)=P(x,y)vec{i}+Q(x,y)vec{j}$$ on an open and simply-connected region. Assume $P$ and $Q$ have continuous partial derivatives.
Under which conditions there exists a positive-valued function $mu (x,y)$ such that $$muvec{F}(x,y)=mu(x,y)P(x,y)vec{i}+mu(x,y)Q(x,y)vec{j}$$ is a conservative vector field?



Thanks for the help!










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    Well, you could start by applying any conditions that you might know of for a vector field to be conservative to $muvec F$.
    – amd
    Nov 15 at 0:21












  • What about $mu(x,y)=0$? (Yes, I know it is a "silly" objection, most likely that's not what you meant. But then you have to be clear about exactly what requirements you have on $mu$.)
    – Arthur
    Nov 15 at 0:22












  • First, thanks for the editing! Second, I would like $μ(x,y)>0$... The idea is that it should preserve the directions in the vector field. I apologize for my poor math knowledge.
    – FreddyM
    Nov 15 at 0:36






  • 2




    To amd. For the field $mu F$ to be conservative, I would need that $$ mu _y P + mu P_y = mu _x Q + mu Q_x $$ which remains difficult for me to investigate! Is the answer trivial?
    – FreddyM
    Nov 15 at 0:40

















up vote
3
down vote

favorite
1












Consider a vector field $$vec{F}(x,y)=P(x,y)vec{i}+Q(x,y)vec{j}$$ on an open and simply-connected region. Assume $P$ and $Q$ have continuous partial derivatives.
Under which conditions there exists a positive-valued function $mu (x,y)$ such that $$muvec{F}(x,y)=mu(x,y)P(x,y)vec{i}+mu(x,y)Q(x,y)vec{j}$$ is a conservative vector field?



Thanks for the help!










share|cite|improve this question




















  • 1




    Well, you could start by applying any conditions that you might know of for a vector field to be conservative to $muvec F$.
    – amd
    Nov 15 at 0:21












  • What about $mu(x,y)=0$? (Yes, I know it is a "silly" objection, most likely that's not what you meant. But then you have to be clear about exactly what requirements you have on $mu$.)
    – Arthur
    Nov 15 at 0:22












  • First, thanks for the editing! Second, I would like $μ(x,y)>0$... The idea is that it should preserve the directions in the vector field. I apologize for my poor math knowledge.
    – FreddyM
    Nov 15 at 0:36






  • 2




    To amd. For the field $mu F$ to be conservative, I would need that $$ mu _y P + mu P_y = mu _x Q + mu Q_x $$ which remains difficult for me to investigate! Is the answer trivial?
    – FreddyM
    Nov 15 at 0:40















up vote
3
down vote

favorite
1









up vote
3
down vote

favorite
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Consider a vector field $$vec{F}(x,y)=P(x,y)vec{i}+Q(x,y)vec{j}$$ on an open and simply-connected region. Assume $P$ and $Q$ have continuous partial derivatives.
Under which conditions there exists a positive-valued function $mu (x,y)$ such that $$muvec{F}(x,y)=mu(x,y)P(x,y)vec{i}+mu(x,y)Q(x,y)vec{j}$$ is a conservative vector field?



Thanks for the help!










share|cite|improve this question















Consider a vector field $$vec{F}(x,y)=P(x,y)vec{i}+Q(x,y)vec{j}$$ on an open and simply-connected region. Assume $P$ and $Q$ have continuous partial derivatives.
Under which conditions there exists a positive-valued function $mu (x,y)$ such that $$muvec{F}(x,y)=mu(x,y)P(x,y)vec{i}+mu(x,y)Q(x,y)vec{j}$$ is a conservative vector field?



Thanks for the help!







multivariable-calculus vector-analysis






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edited Nov 15 at 0:35

























asked Nov 15 at 0:16









FreddyM

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  • 1




    Well, you could start by applying any conditions that you might know of for a vector field to be conservative to $muvec F$.
    – amd
    Nov 15 at 0:21












  • What about $mu(x,y)=0$? (Yes, I know it is a "silly" objection, most likely that's not what you meant. But then you have to be clear about exactly what requirements you have on $mu$.)
    – Arthur
    Nov 15 at 0:22












  • First, thanks for the editing! Second, I would like $μ(x,y)>0$... The idea is that it should preserve the directions in the vector field. I apologize for my poor math knowledge.
    – FreddyM
    Nov 15 at 0:36






  • 2




    To amd. For the field $mu F$ to be conservative, I would need that $$ mu _y P + mu P_y = mu _x Q + mu Q_x $$ which remains difficult for me to investigate! Is the answer trivial?
    – FreddyM
    Nov 15 at 0:40
















  • 1




    Well, you could start by applying any conditions that you might know of for a vector field to be conservative to $muvec F$.
    – amd
    Nov 15 at 0:21












  • What about $mu(x,y)=0$? (Yes, I know it is a "silly" objection, most likely that's not what you meant. But then you have to be clear about exactly what requirements you have on $mu$.)
    – Arthur
    Nov 15 at 0:22












  • First, thanks for the editing! Second, I would like $μ(x,y)>0$... The idea is that it should preserve the directions in the vector field. I apologize for my poor math knowledge.
    – FreddyM
    Nov 15 at 0:36






  • 2




    To amd. For the field $mu F$ to be conservative, I would need that $$ mu _y P + mu P_y = mu _x Q + mu Q_x $$ which remains difficult for me to investigate! Is the answer trivial?
    – FreddyM
    Nov 15 at 0:40










1




1




Well, you could start by applying any conditions that you might know of for a vector field to be conservative to $muvec F$.
– amd
Nov 15 at 0:21






Well, you could start by applying any conditions that you might know of for a vector field to be conservative to $muvec F$.
– amd
Nov 15 at 0:21














What about $mu(x,y)=0$? (Yes, I know it is a "silly" objection, most likely that's not what you meant. But then you have to be clear about exactly what requirements you have on $mu$.)
– Arthur
Nov 15 at 0:22






What about $mu(x,y)=0$? (Yes, I know it is a "silly" objection, most likely that's not what you meant. But then you have to be clear about exactly what requirements you have on $mu$.)
– Arthur
Nov 15 at 0:22














First, thanks for the editing! Second, I would like $μ(x,y)>0$... The idea is that it should preserve the directions in the vector field. I apologize for my poor math knowledge.
– FreddyM
Nov 15 at 0:36




First, thanks for the editing! Second, I would like $μ(x,y)>0$... The idea is that it should preserve the directions in the vector field. I apologize for my poor math knowledge.
– FreddyM
Nov 15 at 0:36




2




2




To amd. For the field $mu F$ to be conservative, I would need that $$ mu _y P + mu P_y = mu _x Q + mu Q_x $$ which remains difficult for me to investigate! Is the answer trivial?
– FreddyM
Nov 15 at 0:40






To amd. For the field $mu F$ to be conservative, I would need that $$ mu _y P + mu P_y = mu _x Q + mu Q_x $$ which remains difficult for me to investigate! Is the answer trivial?
– FreddyM
Nov 15 at 0:40

















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