Infinite Solution to a differential equation problem

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SUMMARY

The discussion focuses on identifying an everywhere continuous function F that leads to infinitely many solutions for the initial value problem y' = F(y), y(0) = 0. A key insight is that if the function f(y) is continuous but not Lipschitz continuous, it can result in multiple solutions. The concept of Lipschitz continuity is crucial, as it lies between mere continuity and having a continuous derivative, impacting the uniqueness of solutions in differential equations.

PREREQUISITES
  • Understanding of differential equations and initial value problems
  • Knowledge of continuity and Lipschitz continuity concepts
  • Familiarity with the properties of continuous functions
  • Basic calculus, particularly derivatives and their implications
NEXT STEPS
  • Study the implications of Lipschitz continuity in differential equations
  • Explore examples of continuous functions that are not Lipschitz continuous
  • Investigate the existence and uniqueness theorems for differential equations
  • Learn about the role of continuous derivatives in solution behavior
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Mathematicians, students of calculus and differential equations, and anyone interested in the behavior of solutions to initial value problems in mathematical analysis.

philthekinggg
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Give an example of an everywhere continuous function F such that the initial value problem y' = F(y), y(0) = 0 has infinitely many solution.


The only function that I have thought of so far that has infinite solutions is y=ey + c, but that obviously doesn't fall under the condition of y(0) = 0.
 
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Do you remember the requirement for uniqueness of solutions to differential equations?
If you have a differential equation of the form y'(x) = f(y), where f(y) is continuous, but not Lipschitz continuous, then that might work!
 
"Lispschitz" lies part way between "continuous" and "has a continuous derivative" (many textbooks give "has a continuous derivative" as a sufficient but not necessary condition for existence and uniqueness) so if you use a function that is continuous but does not differentiable with respect to y, that will be sufficient.
 

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