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0
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avatar+2353 

Okay so I have these questions

With these answers

Now I don't entirely understand what's happening here.

I do understand part a) (but I included it to save you some calculations)

In part b) it is apparently true that an equilibrium solution is asymptotically stable if $$|\lambda_k|<1 \mbox{ } \forall \mbox{ } k$$

where $$\lambda_k$$ is an eigenvalue of the jacobian matrix. Even though intuitively this does seem to make sense, can someone explain this to me?

 

Then for part c), they say that the $$(c_1_-,c_1_-)$$ equilibrium solution is asymptotically stable for all $$a>0$$ while in part b) it was stated that both equilibrium solutions for  $$a=\frac{1}{2} , b = \frac{1}{2}$$ were not asymptotically stable. Perhaps I'm missing something here, but to me this appears as a contradiction.

 

Reinout 

 Jun 5, 2014

Best Answer 

 #1
avatar+11912 
+6

oh reinout , i wish i could help u but the math is like " from another world from me " so i cant help ! but i can give u my very famous " all the bast " lol! so i hope u succed in ur search for help ! 

 Jun 6, 2014
 #1
avatar+11912 
+6
Best Answer

oh reinout , i wish i could help u but the math is like " from another world from me " so i cant help ! but i can give u my very famous " all the bast " lol! so i hope u succed in ur search for help ! 

rosala Jun 6, 2014
 #2
avatar+33661 
+5

When it says for all a>0, it has already specified that a must be less than 1/4, so I think it means in the range 0<a<1/4.  I might be wrong about this as, for the (r,s) solution it explicitly gives the range as 0 to 3/16.

I calculated the iterates for starting values of (0, 0) and a few different a values (b = 1/2 in all cases).  They look like this:

iterates

 

Where succesive iterates are not converging they are clearly oscillating between two values.

Hope this helps rather than confuses!

(Edited to upload the correct figures!)

 Jun 6, 2014
 #3
avatar+893 
+5

Hi Reinout

Are you still interested in this question or have you got it sorted ?

 Jun 9, 2014
 #4
avatar+893 
+5

Bertie Jun 10, 2014
 #5
avatar+893 
+5

Bertie Jun 10, 2014
 #6
avatar+893 
0

That's my attempt at the early theory for this question

You have to pretend that the two posts are a single post !

I don't agree with the analysis for the last part of the question, my analysis to follow.

 Jun 10, 2014
 #7
avatar+893 
+5

Bertie Jun 11, 2014
 #8
avatar+2353 
0

Thanks Bertie, that does make sense. 

It was the last part I was most puzzled about though.

I guess I'll have to consider that part poorly defined.

 Jun 11, 2014

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