Help putting differential equations into matrix form

In summary, the conversation discusses arranging a system of inhomogeneous differential equations into matrix form and finding the general solution using the matrix exponential. The conversation also includes a request for help with handling a term that does not have a corresponding derivative.
  • #1
hajjar0415
2
0

Homework Statement



Hello, I am trying to put the following equations into matrix form in order to solve the system. If anyone could please explain to me how to do it or show me an example it would be awesome.

All material given in question:

For the system of inhomogeneous differential equations,
dx/dt = 5x-y+2

dy/dt = x + 3y – 4t

and the initial condition, x(0)=1 and y(0)=2.

a)Arrange the system into matrix form
b)Find the diagonal or Jordan form of the system matrix
c)Write the general solution in the form of the matrix exponential
d)Use the initial condition to find the solution x(t) and y(t)

Thanks for any help

Homework Equations





The Attempt at a Solution



I am aware that the matrix has to be square in order to proceed.

What i have so far is:

[5 -1 0 ] [x] + [2]
[1 3 -4 ] [y] + [0]
[0 0 0 ] [t] + [0]

The -4t is what is throwing me off because there is no dt/dt equation given so i have put all 0's in the matrix.
 
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  • #2
##t## is your independent variable. Write your system in the form$$
\begin{bmatrix} x'\\y'
\end{bmatrix}=
\begin{bmatrix}
a&b\\c&d
\end{bmatrix}
\begin{bmatrix}
x\\y
\end{bmatrix}+
\begin{bmatrix}
f(t)\\g(t)
\end{bmatrix}$$
 
  • #3
So would the matrix form be:

5 -1 , x + 2
1 3 ,y + -4t

thanks for the help
 
  • #4
hajjar0415 said:
So would the matrix form be:

5 -1 , x + 2
1 3 ,y + -4t

thanks for the help

I showed you one form. But yours isn't like mine because you have no derivatives nor equals signs. Surely your text shows you what form to use.
 

FAQ: Help putting differential equations into matrix form

What is the purpose of putting differential equations into matrix form?

Putting differential equations into matrix form is a useful technique for solving systems of differential equations. It allows for a more efficient and organized way to represent the equations and find solutions.

How do you convert a differential equation into matrix form?

To convert a differential equation into matrix form, you first need to rearrange the equation so that all derivatives are on one side and all other terms are on the other side. Then, you can represent the derivatives as matrices and the other terms as a vector. Finally, you can combine these matrices and vector to form a matrix equation.

Can any differential equation be converted into matrix form?

No, not all differential equations can be converted into matrix form. Only systems of linear differential equations can be converted into matrix form. Nonlinear differential equations cannot be represented as matrices.

Why is it important to use matrix form for solving differential equations?

Using matrix form for solving differential equations allows for a more efficient and systematic approach to finding solutions. It also allows for the use of various matrix operations and techniques, such as Gaussian elimination, which can simplify the solving process.

Are there any limitations to using matrix form for solving differential equations?

While matrix form is a powerful tool for solving systems of linear differential equations, it may not always be the most practical or efficient method. In some cases, other techniques such as Laplace transforms or numerical methods may be more suitable for solving certain types of differential equations.

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