Initial Value Linear system of DQ's

scorpius1782
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Homework Statement


The unique solution of the linear system of differential equations
##\frac{dv}{dt}=-34v+ -16w, v(0)=-1##
##\frac{dw}{dt}=80v+ 38w, w(0)=-3##
is: (enter the smaller of the eigenvalues first, and note that all entries here are integers)
##v(t)= C_1 e^{-2t}+C_2 e^{6t}##
##w(t)= C_3 e^{-2t}+C_4 e^{6t}##

I plugged in the exponential values since they're easy to get and not my problem.
Since I already know the answer to this practice problem:
##C_1=-11##
##C_2=10##
##C_3=22##
##C_4=-25##

Homework Equations





The Attempt at a Solution



I just can't figure out how they get the constants.

The eigenvalues are -2 and 6. And the eigenvectors are [-1,2] and [-2, 5]

I thought I was suppose to set the vectors in a matrix and set equal to the initial values but this doesn't work in anyway I've tried at all. I see that C1+C2=-1 and that the other two constants add up to -3 but I have no clue how they picked out those numbers. The example we did in class only had 1 constraint and was an annoyingly simple problem.

I've done everything I can think of to extract the method but am just missing the method. I'm sure it will be very simple. If anyone can please help me I'd appreciate it.
 
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Nevermind, solved it.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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