- #1

jeffy

- 17

- 0

## Homework Statement

dx/dt= -4x -y

dy/dt= x-2y

x(0)=4 y(0)=1

x(t)=?

y(t)=?

## Homework Equations

## The Attempt at a Solution

1) find eigenvalues

(x+4)(X+2)+1

X=-3,-3

2)eigenvectors:

(-3-A)(x,y)=(0,0)

eignvector=(-1,1)

3)using the P from this page http://tutorial.math.lamar.edu/Classes/DE/RepeatedEigenvalues.aspx

i found P to be (-1,0)

4) so i plugged the eigenvector and the P into the solution for repeated eigenvalues in the link above and got C1=1 and C2=-5

5) plugging those values in i got x=4e^(-3t)+(5t)e^(-3t) and y=e^(-3t)-(5t)e^-3t

however when i entered this into the program(igot all the syntax right) my answer is wrong and ive tried it many times