MHB Find Steady States for Equations: u, v and Get Help with Steady State Question

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The discussion revolves around finding steady states for two equations involving variables u and v. The user identifies three steady states: (0,0), (1,0), and (-a,0), derived from substituting v=0 into the first equation. They also explore substituting u=c/b, which leads to a fourth steady state solution of (c/b, a + c/b - ac/b - c^2/b^2). The user seeks confirmation on their calculations and clarity on the substitution process, indicating some confusion in the latter part of their working. Overall, the thread focuses on verifying the correctness of steady state solutions for the given equations.
mt91
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Got a steady state question and was wondering if anyone would be able to check if I'm on the right track?

Find the steady states of these two equations:

1596287107517.png


My working out as far:

\[ 0=u*(1-u*)(a+u*)-u*v* \]
\[ 0=v*(bu*-c) \]

I looked at the 2nd equation first giving:
\[ v*=0, u*=c/b \]

subbing v*=0 into equation 1 gave:
\[ 0=u*(1-u*)(a+u*) \]
\[ u*=0, u*=1, u*=-a \]
\[ v=a+c/b - ac/b-c^2/b^2 \]

Not sure about that part of the steady state question so any help would be really helpful, cheers

Giving three steady states of
(0,0), (1,0), (-a,0)

Then I looked at subbing u*=b/c. (However this part of my working got confusing and I'm not entirely sure if it was correct.

\[ 0=c/b(1-c/b)(a+c/b)-cv/b \]
\[ cv/b=c/b-c^2/b^2(a+c/b) \]
 
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mt91 said:
Got a steady state question and was wondering if anyone would be able to check if I'm on the right track?

Find the steady states of these two equations:

View attachment 10548

My working out as far:

\[ 0=u*(1-u*)(a+u*)-u*v* \]
\[ 0=v*(bu*-c) \]

I looked at the 2nd equation first giving:
\[ v*=0, u*=c/b \]
Either v*= 0 or u*=c/b

subbing v*=0 into equation 1 gave:
\[ 0=u*(1-u*)(a+u*) \]
\[ u*=0, u*=1, u*=-a \]
Yes, (u*, v*)= (0, 0), (1, 0), and (-a, 0) are three steady state solutions.

\[ v=a+c/b - ac/b-c^2/b^2 \]
Yes, substituting u*= c/b into 0=u*(1-u*)(a+u*)-u*v* gives 0= (c/b)(1- c/b)(a+ c/b)- (c/b)v* .
(c/b)v*= (c/b)(1- c/b)(a+ c/b) so v*= (1- c/b)(a+ c/b)= a- ac/b+ c/b- c^2/b^2

So a fourth steady state solution is (u*, v*)= (c/b, a+ c/b- ac/b- c^2/b^2).

Not sure about that part of the steady state question so any help would be really helpful, cheers

Giving three steady states of
(0,0), (1,0), (-a,0)

Then I looked at subbing u*=b/c. (However this part of my working got confusing and I'm not entirely sure if it was correct.

\[ 0=c/b(1-c/b)(a+c/b)-cv/b \]
\[ cv/b=c/b-c^2/b^2(a+c/b) \]
 
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