Tow questions ( differential equation )

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SUMMARY

This discussion focuses on solving two questions related to the stability of critical points in autonomous systems of differential equations. The first question involves the system defined by dx/dt = g(y) and dy/dt = g(x), where it is established that the critical point (0,0) is unstable if g'(0) > 0 and asymptotically stable if g'(0) < 0. The second question examines the system dx/dt = f(y) and dy/dt = g(x), demonstrating that (0,0) is a critical point, with the nature of stability determined by the product f'(0)g'(0). If f'(0)g'(0) > 0, (0,0) is a saddle point; if f'(0)g'(0) < 0, it is a center or spiral point.

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  • Understanding of autonomous systems in differential equations
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  • Familiarity with derivatives and their implications in dynamical systems
  • Experience with functions and their higher-order derivatives
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Mathematicians, students of differential equations, and researchers in dynamical systems who are analyzing stability in autonomous systems.

little_lolo
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Please can you solve this tow questions today...



Q1) If g is a function such that g(0)=0 and all high order derivatives exist consider the
autonomous system

dx/dt = g(y) dy/dt = g(x)

a. show that (o.o) is critical point and that system is almost linear in the neighborhood of (o.o)


b. show that if g'(o)>o then critical point (o,o) is unstable and that if g'(o)<o then the critical point is asymptotically stable


c. show that the critical point (o,o) is a saddle point and unstable






Q2) consider the system

dx/dt =f(y) dy/dt =g(x)

where f,g are functions whit all their higher derivatives exist and f(o)=g(o)=o and f'(0)≠0 g'(o)≠o


a. show that (o.o) is critical point of the system and the system is almost linear system at it.




b. show that if f'(0)g'(0)>0 then the critical point (0.0) is a saddle point and if f'(0)g'(0)<0 then the critical point (0.0) is a center or spiral point



thank you

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