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Toronto Math Forum
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MAT244-2014F
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MAT244 Math--Tests
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Quiz 4
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Q4 problem 2
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Topic: Q4 problem 2 (Read 6149 times)
Yuan Bian
Jr. Member
Posts: 14
Karma: 4
Q4 problem 2
«
on:
November 12, 2014, 09:03:38 PM »
Q2: 7.6 #6
r
2
+9=0
r
1
=3i, r2=-3i
pure imaginary eigenvalue, so it's stable center
also whole soln is in the q1 fisrt post.
«
Last Edit: November 12, 2014, 10:25:37 PM by Victor Ivrii
»
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Guang_Yang
Newbie
Posts: 2
Karma: 1
Re: Q4
«
Reply #1 on:
November 12, 2014, 09:53:49 PM »
7.6 #6
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Tao Hu
Jr. Member
Posts: 6
Karma: 3
Re: Q4 problem 2
«
Reply #2 on:
November 13, 2014, 03:36:44 PM »
How to determine the direction of the circular phase portrait? What is the difference between clockwise and anti-clockwise?
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Yuan Bian
Jr. Member
Posts: 14
Karma: 4
Re: Q4 problem 2
«
Reply #3 on:
November 13, 2014, 09:13:45 PM »
from prof Victor Ivrii :
"Why you just don't learn a very simple criteria for the center or focus:
if the top-right element of 2×2 matrix is >0 the orientation is clock-wise; otherwise it is counter-clock-wise."
«
Last Edit: November 13, 2014, 09:21:54 PM by Yuan Bian
»
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Shuyang Wang
Newbie
Posts: 3
Karma: 4
Re: Q4 problem 2
«
Reply #4 on:
November 13, 2014, 09:52:56 PM »
Just a plot by software
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Toronto Math Forum
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MAT244-2014F
»
MAT244 Math--Tests
»
Quiz 4
»
Q4 problem 2