If we apply the laplace transform to our system: sx−X(0)=Ax => x=(sI−A)^(-1)X(0). The solution is obtained when we apply the inverse laplace transform. How could I solve such a system when I'm given a vector not at 0?

Hugo Stokes

Hugo Stokes

Answered question

2022-10-29

Suppose we have a system X = A X. Let's denote the laplace transform of a vector Y as L { Y ( t ) } ( s ) = y ( s ). If we apply the laplace transform to our system:
s x X ( 0 ) = A x x = ( s I A ) 1 X ( 0 ) .
The solution is obtained when we apply the inverse laplace transform. How could I solve such a system when I'm given a vector not at 0?

Answer & Explanation

lipovicai1w

lipovicai1w

Beginner2022-10-30Added 9 answers

To solve X = A X with X ( t 0 ) = b given, solve Y = A Y with Y ( 0 ) = b, and take X ( t ) = Y ( t t 0 )
Evelyn Freeman

Evelyn Freeman

Beginner2022-10-31Added 5 answers

I edited first's answer. However it was not accepted. Here there is a more explicit explanation of his idea:
Consider the change of variables:
X ( t ) = Y ( t t 0 ) .
Therefore the system
{ X ( t ) = A X ( t ) X ( t 0 ) = b
is equivalent to the system
{ Y ( t t 0 ) = A Y ( t t 0 ) Y ( 0 ) = b .
If you solve the last system you will obtain a solution Y ( t t 0 ) = X ( t ) which is the solution to the initial system.

Do you have a similar question?

Recalculate according to your conditions!

New Questions in Differential Equations

Ask your question.
Get an expert answer.

Let our experts help you. Answer in as fast as 15 minutes.

Didn't find what you were looking for?