lecture19matrixprob1

lecture19matrixprob2

 

so now we have where  and where

and the  matrix is .  Its determinant is (e-t)(-2e-4t)-(e-t)(e-4t)= - 3e-5t

 

Its inverse-1 is

 

Note:  The  matrix can be written as the product of the T and Q matrices ONLY if the roots of the eigenvalues equation are distinct

 

Suppose you wanted to solve    +

Since we have already solved for the  matrix and found the inverse, namely, -1 is , we have to find

 

=

 

integrate this to get d =  and this must be multiplied by  to get ζp

 

that is ζp= X   =   and, finally,

 

zp=

 

 

 

The total solution is then  .  It should be noted that it is on this that we apply the initial conditions. 

 

You would have to be given an initial condition for each state variable in order to obtain a complete solution.