Error, (in ODEtools/info) x(t) and x cannot both appear in the given ODE.

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Homework Help Overview

The discussion revolves around a separable differential equation being solved in Maple, specifically the equation involving the derivative of x(t) with respect to time t. Participants are exploring the error message received when attempting to solve the equation due to the use of different symbols for the same variable.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the interpretation of variable names in Maple, questioning the distinction between "x(t)" as a function and "x" as a constant. There is an exploration of how to properly format the equation for Maple to accept it.

Discussion Status

The discussion is focused on clarifying the error message from Maple and understanding the implications of using different symbols for the same variable. Some participants have provided insights into the nature of the error, while others are confirming the correct way to express the equation in Maple.

Contextual Notes

There are no initial conditions provided for the differential equation, which may influence the discussion on solving it. Participants are navigating the constraints imposed by Maple's syntax and error reporting.

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Homework Statement



Hi I am trying to solve a seperable differential equation in Maple

eqn1:=diff(x(t),t)=3*t^2/sqrt(x);

But every time I type

dsolve(eqn1,x(t));

I get the very hurtfull error from Maple

"Error, (in ODEtools/info) x(t) and x cannot both appear in the given ODE."

What am I doing wrong?

I have changed it to

eqn1:=diff(x(t),t)=3*t^2/sqrt(x(t)); and Mapple accepted it...

Is this right?
 
Last edited:
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"x(t)" and "x" are different symbols. Maple is interpreting "x(t)" as a function of t and "x" as a constant. It appears to Maple that you are using "x" in two different ways and it will not allow that.
 
HallsofIvy said:
"x(t)" and "x" are different symbols. Maple is interpreting "x(t)" as a function of t and "x" as a constant. It appears to Maple that you are using "x" in two different ways and it will not allow that.

Okay why Hallsoftivy could they go ahead and write this in the error insteed :)

But thank you :)

I'm given the differential equation

[tex]\frac{dx}{dt} = \frac{3t^2}{\sqrt{x}}[/tex]

without any initial conditions

the right way to solve this in Maple is the command:
eqn1:=diff(x(t),t)=3*t^2/sqrt(x(t));

??
 
Last edited:
? That's what I just said: Maple is telling you that you cannot use the letter "x" in two different meanings and that is how Maple is interpreting what you gave.
 

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