Inhomogenous ODEs, Particular solutions question

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In summary, the conversation is about finding a particular solution for the differential equation d^2x/dt^2 + 4(dx/dt) + 3x = (3t/2) -4, given the boundary conditions of x=0 and dx/dt=0 at t=0. The conversation mentions finding the homogeneous solution and using the RHS of the equation to find the particular solution, with the suggestion of using x(t)=a*t+b as a possible form for the particular solution.
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Moham1287
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1.The position of a particle x(t) obeys the following differential equation

d^2x/dt^2 + 4(dx/dt) + 3x = (3t/2) -4

If at t=0, both x=0 and dt/dx=0, find x(t)






Attempt at solution
I've found the homogeneous solution to be y=Aexp(-3x) + Bexp(-x), and know how to find x(t) given boundary conditions, but I'm having trouble finding the particular solution. I know you have to use g(x) where g(x) is the RHS of the equation, but when I try using Yp=r exp(mu x) or a combination of factors of x, I get a load of rubbish. Can anyone please help?
 
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If you look at the form of the RHS, you might guess that a particular solution would have the form x(t)=a*t+b. Put that into the equation at try to find a and b. You first try at finding a particular solution should always be to try and guess what it could be and then prove yourself right.
 

1. What is an inhomogenous ODE?

An inhomogenous ODE is a type of Ordinary Differential Equation (ODE) that includes a non-zero function on the right-hand side of the equation. This means that the equation is not equal to zero, unlike a homogeneous ODE where the right-hand side is equal to zero.

2. What is the difference between a particular solution and a general solution for inhomogenous ODEs?

A particular solution is a specific solution to an inhomogenous ODE that satisfies both the equation and any given initial conditions. It is unique and can be found by using specific methods such as variation of parameters or undetermined coefficients. On the other hand, a general solution is a family of solutions that includes all possible solutions to the inhomogenous ODE, and it can be obtained by solving the associated homogeneous equation.

3. How do you find the particular solution for an inhomogenous ODE?

The particular solution for an inhomogenous ODE can be found by using methods such as variation of parameters or undetermined coefficients. These methods involve finding a particular form of the solution and solving for the unknown coefficients using the given initial conditions. Another approach is to use the Green's function method, which involves finding the Green's function for the inhomogenous ODE and applying it to the right-hand side of the equation to obtain the particular solution.

4. Can an inhomogenous ODE have multiple particular solutions?

No, an inhomogenous ODE can only have one particular solution. This is because the particular solution is unique and satisfies both the equation and any given initial conditions. However, there can be multiple general solutions for an inhomogenous ODE, as it is a family of solutions that includes all possible solutions.

5. What are some real-life applications of inhomogenous ODEs?

Inhomogenous ODEs have numerous applications in science and engineering, including modeling processes in physics, chemistry, and biology. For example, they can be used to describe the motion of a pendulum, the decay of radioactive materials, or the spread of diseases. Inhomogenous ODEs are also commonly used in engineering to model systems such as electrical circuits, mechanical systems, and chemical reactions.

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