Basis for the space of solutions (ODE)

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Homework Help Overview

The discussion revolves around finding a basis for the space of solutions to the ordinary differential equation (ODE) given by dy/dt = 3*y. Participants are exploring the nature of the solution space and the appropriate representation of the basis.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the validity of the proposed solution, e^(3*t), and question why it may not be accepted as correct. There is mention of a basis being described as a set of functions, leading to confusion about the representation of the solution space.

Discussion Status

Some participants express understanding of the solution and its representation, while others are uncertain about the requirements for the basis notation. There is a recognition that the solution space consists of infinitely many functions, and the need for clarification on the expected format is highlighted.

Contextual Notes

Participants note potential issues with how the solution is being graded or formatted, suggesting that the representation in set notation may be a requirement. There is also a mention of the possibility of a technical problem with the grading system.

Poetria
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Homework Statement



The equation given:

dy/dt = 3*y

A basis for the space of solutions is required.

The Attempt at a Solution



According to me it is e^(3*t) but it has turned out false. Why? I am considering the answer "The basis is the set of all functions of the form c*e^(3*t) but a different example was described as follows:
"The vector space of solutions to a homogeneous ODE consists of infinitely many functions. To describe it compactly, we give a basis of the vector space. In this case, the basis has only 2 functions."

Is it possible that my answer is correct and there is a bug here?
 
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Poetria said:

Homework Statement



The equation given:

dy/dt = 3*y[/B]

A basis for the space of solutions is required.

The Attempt at a Solution



According to me it is e^(3*t) but it has turned out false. Why? I am considering the answer "The basis is the set of all functions of the form c*e^(3*t) but a different example was described as follows:
"The vector space of solutions to a homogeneous ODE consists of infinitely many functions. To describe it compactly, we give a basis of the vector space. In this case, the basis has only 2 functions."

Is it possible that my answer is correct and there is a bug here?
[/B]

What is their basis? What is the vector space you are working in? Those are essential things to know.

You are right to say that ##y(t) = Ae^{3t}## is the solution of this differential equation.
 
Poetria said:

Homework Statement



The equation given:

dy/dt = 3*y[/B]

A basis for the space of solutions is required.

The Attempt at a Solution



According to me it is e^(3*t) but it has turned out false. Why? I am considering the answer "The basis is the set of all functions of the form c*e^(3*t) but a different example was described as follows:
"The vector space of solutions to a homogeneous ODE consists of infinitely many functions. To describe it compactly, we give a basis of the vector space. In this case, the basis has only 2 functions."

Is it possible that my answer is correct and there is a bug here?
[/B]
You are correct that the function ##e^{3t}## is a basis for the solution space. Perhaps the problem is typing it in a particular format for an online problem? Maybe they want something like ##\{e^{3t}\}##. In any case, you do understand it correctly.
 
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LCKurtz said:
You are correct that the function ##e^{3t}## is a basis for the solution space. Perhaps the problem is typing it in a particular format for an online problem? Maybe they want something like ##\{e^{3t}\}##. In any case, you do understand it correctly.

Many thanks. :) It is the main thing to understand it correctly. :) I will ask if this is a technical problem with a grader.
 
Poetria said:
Many thanks. :) It is the main thing to understand it correctly. :) I will ask if this is a technical problem with a grader.
I will guess that they want the set notation, since a basis is a set of functions. In this case, a set containing a single function.
 
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LCKurtz said:
I will guess that they want the set notation, since a basis is a set of functions. In this case, a set containing a single function.

I can only tick 'one', 'two' etc. I can't add the set notation. Perhaps 'none' of possibilities is the right answer. :) This is annoying.
 

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