Is f a Continuous Function with a Fixed Point on [a,b]?

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SUMMARY

The discussion centers on proving the continuity of a function f defined on the interval [a,b] and demonstrating that it has a fixed point within the same interval. The key condition provided is that for all (x,t) in [a,b]^2, the inequality |f(x) - f(t)| < |x - t| holds. To establish continuity, participants recommend using the formal definition of continuity. For the fixed point, the transformation f(x) - x is suggested as a method to analyze the existence of a steadfast point.

PREREQUISITES
  • Understanding of the definition of continuity in mathematical analysis
  • Familiarity with fixed point theorems
  • Knowledge of inequalities and their implications in function behavior
  • Basic skills in limit definitions and proofs
NEXT STEPS
  • Study the formal definition of continuity in real analysis
  • Explore fixed point theorems, particularly the Banach Fixed-Point Theorem
  • Review examples of functions that satisfy the given inequality condition
  • Practice proving continuity using epsilon-delta definitions
USEFUL FOR

Students in advanced mathematics, particularly those studying real analysis, as well as educators and anyone interested in the properties of continuous functions and fixed point theory.

mtayab1994
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Homework Statement



Let f be q function defined from [a,b] to [a,b] such that for every (x,t) in [a,b]^2:

l f(x)-f(t) l < l x-t l

1- prove that f is continuous on [a;b]

2-prove that f accepts a steadfast point in [a,b]

The Attempt at a Solution


Should i try to use the definition of a limit to show that f is continuous?
If not can someone give me headers. Thank you very much
 
Last edited:
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Yes, for part 1, use the definition of continuity.

For part 2, I assume "accepts a steadfast point" means "has a fixed point." If so, consider the function defined by f(x) - x.
 

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