Linear system of differential equations given a solution












0












$begingroup$


I am asked to Give an example of a linear system for which $(e^{−t} , alpha)$ is a solution for every constant $alpha$ and to give the general solution for this system. I came up with a linear system based on my understanding,but it seems wrong to me, and I would like some guidance on how to approach this type of problem



From what I understand we can broadly describe a linear system of differential equations as
$$x_1' = f(t,x_1,x_2)\ x_2' = f(t,x_1, x_2)$$



and so since I am given the solution $(e^{-t}, alpha)=(x_1(t), x_2(t))$, A linear system for which this is a solution can be given by



$$x_1' = -e^{-t}\ x_2' = 0$$



but to me this appears too simple and incorrect. If so how do I go about approaching such a problem?










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$endgroup$












  • $begingroup$
    It seems that you think that $(e^{-t})'=-te^{-t}$.
    $endgroup$
    – John B
    Jan 24 at 22:56










  • $begingroup$
    apoligies, I will correct my error
    $endgroup$
    – Richard Villalobos
    Jan 24 at 23:13






  • 1




    $begingroup$
    Good, so you can consider the equation $x_1'=-x_1$.
    $endgroup$
    – John B
    Jan 24 at 23:46










  • $begingroup$
    Ah thank you, I understand now! I was complicating things for myself by assuming that the specific solution I was given could describe the entire system instead of being more general. Thank you!
    $endgroup$
    – Richard Villalobos
    Jan 24 at 23:49
















0












$begingroup$


I am asked to Give an example of a linear system for which $(e^{−t} , alpha)$ is a solution for every constant $alpha$ and to give the general solution for this system. I came up with a linear system based on my understanding,but it seems wrong to me, and I would like some guidance on how to approach this type of problem



From what I understand we can broadly describe a linear system of differential equations as
$$x_1' = f(t,x_1,x_2)\ x_2' = f(t,x_1, x_2)$$



and so since I am given the solution $(e^{-t}, alpha)=(x_1(t), x_2(t))$, A linear system for which this is a solution can be given by



$$x_1' = -e^{-t}\ x_2' = 0$$



but to me this appears too simple and incorrect. If so how do I go about approaching such a problem?










share|cite|improve this question











$endgroup$












  • $begingroup$
    It seems that you think that $(e^{-t})'=-te^{-t}$.
    $endgroup$
    – John B
    Jan 24 at 22:56










  • $begingroup$
    apoligies, I will correct my error
    $endgroup$
    – Richard Villalobos
    Jan 24 at 23:13






  • 1




    $begingroup$
    Good, so you can consider the equation $x_1'=-x_1$.
    $endgroup$
    – John B
    Jan 24 at 23:46










  • $begingroup$
    Ah thank you, I understand now! I was complicating things for myself by assuming that the specific solution I was given could describe the entire system instead of being more general. Thank you!
    $endgroup$
    – Richard Villalobos
    Jan 24 at 23:49














0












0








0





$begingroup$


I am asked to Give an example of a linear system for which $(e^{−t} , alpha)$ is a solution for every constant $alpha$ and to give the general solution for this system. I came up with a linear system based on my understanding,but it seems wrong to me, and I would like some guidance on how to approach this type of problem



From what I understand we can broadly describe a linear system of differential equations as
$$x_1' = f(t,x_1,x_2)\ x_2' = f(t,x_1, x_2)$$



and so since I am given the solution $(e^{-t}, alpha)=(x_1(t), x_2(t))$, A linear system for which this is a solution can be given by



$$x_1' = -e^{-t}\ x_2' = 0$$



but to me this appears too simple and incorrect. If so how do I go about approaching such a problem?










share|cite|improve this question











$endgroup$




I am asked to Give an example of a linear system for which $(e^{−t} , alpha)$ is a solution for every constant $alpha$ and to give the general solution for this system. I came up with a linear system based on my understanding,but it seems wrong to me, and I would like some guidance on how to approach this type of problem



From what I understand we can broadly describe a linear system of differential equations as
$$x_1' = f(t,x_1,x_2)\ x_2' = f(t,x_1, x_2)$$



and so since I am given the solution $(e^{-t}, alpha)=(x_1(t), x_2(t))$, A linear system for which this is a solution can be given by



$$x_1' = -e^{-t}\ x_2' = 0$$



but to me this appears too simple and incorrect. If so how do I go about approaching such a problem?







ordinary-differential-equations systems-of-equations






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 24 at 23:13







Richard Villalobos

















asked Jan 24 at 22:41









Richard VillalobosRichard Villalobos

1807




1807












  • $begingroup$
    It seems that you think that $(e^{-t})'=-te^{-t}$.
    $endgroup$
    – John B
    Jan 24 at 22:56










  • $begingroup$
    apoligies, I will correct my error
    $endgroup$
    – Richard Villalobos
    Jan 24 at 23:13






  • 1




    $begingroup$
    Good, so you can consider the equation $x_1'=-x_1$.
    $endgroup$
    – John B
    Jan 24 at 23:46










  • $begingroup$
    Ah thank you, I understand now! I was complicating things for myself by assuming that the specific solution I was given could describe the entire system instead of being more general. Thank you!
    $endgroup$
    – Richard Villalobos
    Jan 24 at 23:49


















  • $begingroup$
    It seems that you think that $(e^{-t})'=-te^{-t}$.
    $endgroup$
    – John B
    Jan 24 at 22:56










  • $begingroup$
    apoligies, I will correct my error
    $endgroup$
    – Richard Villalobos
    Jan 24 at 23:13






  • 1




    $begingroup$
    Good, so you can consider the equation $x_1'=-x_1$.
    $endgroup$
    – John B
    Jan 24 at 23:46










  • $begingroup$
    Ah thank you, I understand now! I was complicating things for myself by assuming that the specific solution I was given could describe the entire system instead of being more general. Thank you!
    $endgroup$
    – Richard Villalobos
    Jan 24 at 23:49
















$begingroup$
It seems that you think that $(e^{-t})'=-te^{-t}$.
$endgroup$
– John B
Jan 24 at 22:56




$begingroup$
It seems that you think that $(e^{-t})'=-te^{-t}$.
$endgroup$
– John B
Jan 24 at 22:56












$begingroup$
apoligies, I will correct my error
$endgroup$
– Richard Villalobos
Jan 24 at 23:13




$begingroup$
apoligies, I will correct my error
$endgroup$
– Richard Villalobos
Jan 24 at 23:13




1




1




$begingroup$
Good, so you can consider the equation $x_1'=-x_1$.
$endgroup$
– John B
Jan 24 at 23:46




$begingroup$
Good, so you can consider the equation $x_1'=-x_1$.
$endgroup$
– John B
Jan 24 at 23:46












$begingroup$
Ah thank you, I understand now! I was complicating things for myself by assuming that the specific solution I was given could describe the entire system instead of being more general. Thank you!
$endgroup$
– Richard Villalobos
Jan 24 at 23:49




$begingroup$
Ah thank you, I understand now! I was complicating things for myself by assuming that the specific solution I was given could describe the entire system instead of being more general. Thank you!
$endgroup$
– Richard Villalobos
Jan 24 at 23:49










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