Differential equation with only the trivial solution

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Homework Help Overview

The discussion revolves around finding a differential equation whose only solution is the trivial solution y=0. Participants are exploring the nature of such equations and questioning whether they exist.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Some participants express uncertainty about the existence of a differential equation with only y=0 as a solution and seek clarification on this point. Others suggest considering functions of y' that cannot be zero, and there are discussions about the implications of complex-valued solutions.

Discussion Status

The conversation is ongoing, with various approaches being proposed. Some participants have suggested specific forms of differential equations, while others are questioning the validity and nontriviality of these suggestions. There is no explicit consensus yet, but the exploration of ideas appears to be productive.

Contextual Notes

Participants are considering the implications of complex-valued solutions and the potential connection to Wronskian matrices. There is a sense of uncertainty regarding the constraints of the problem and the nature of the solutions being sought.

Bipolarity
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Homework Statement


Find a differential equation with its only (complex-valued) solution being y=0

Homework Equations


The Attempt at a Solution


I believe that there is no DE having only y=0 as its solution, but frankly I am not sure if this is the case. I would like to know whether or not this is true, so that I know in which direction I can begin working my proof (or at least a hint is appreciated).

Also, something (in my mind) tells me this problem may have some connection with Wronskian matrices, but I have no clue really.

EDIT: I tried playing with some random diff Eqs, it seems that there are in fact trivial things like y+y'-y'=0, but this type of answer seems to be trivial to be of substance. Is there a DE that does not reduce to a trivial y=0?

Thanks!

BiP
 
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One approach is to think of a function of y' that cannot be zero, f(y') say, then write f(y')y = 0.
 
haruspex said:
One approach is to think of a function of y' that cannot be zero, f(y') say, then write f(y')y = 0.

Well, f(y')=1 works. Still seems like kind of a cheat. Notice they also said complex valued. So something like f(y')=1+(y')^2 won't work either. Not to say you can't cook one up. Like f(y')=(1+(y')(y'*)). I'm just wondering if there is something nontrivial here.
 
Last edited:
I was thinking of ey'y=0
 
haruspex said:
I was thinking of ey'y=0

Good work! And thanks!

BiP
 

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