Existence of a unique solution?

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SUMMARY

The discussion centers on the theorem for the existence of a unique solution to a differential equation (DE) in the context of the equation dy/dx = x - y. It establishes that if the function f(x,y) = x - y and its partial derivative ∂f/∂y = -1 are continuous in a rectangular region R containing the point (xo, yo), then a unique solution exists. The participants confirm that since f(x,y) is continuous for all real values of x and y, the solution to the differential equation is indeed unique everywhere.

PREREQUISITES
  • Understanding of differential equations and their solutions
  • Knowledge of continuity in functions and partial derivatives
  • Familiarity with the concept of rectangular regions in the xy plane
  • Basic principles of the existence and uniqueness theorem for DEs
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  • Study the existence and uniqueness theorem for differential equations in detail
  • Explore examples of differential equations with unique solutions
  • Learn about the implications of continuity in functions and their derivatives
  • Investigate rectangular regions in the context of differential equations
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Students studying differential equations, educators teaching calculus concepts, and mathematicians interested in the properties of solutions to DEs.

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Homework Statement



The theorem for a unique solution to a DE says: Let R be a rectangular region in the xy plane that contains the point (xo,yo). If f(x,y), which = dy/dx and the partial derivative of f(x,y) are continuous on R, then a unique solution exists in that region.

Question: Determine a region of the xy plane for which the given differential equation would have a unique solution.

dy/dx= x-y

dy/dx= f(x,y)= x-y ,so f(x,y) is continuous on all reals for x & y

then
[tex]\partial[/tex]f/[tex]\partial[/tex]y = -1

So this means that the solution is unique everywhere, right?
 
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Yes, f and it's partial derivative are continuous everywhere. The solution is unique.
 

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