Proving Rudin Theorem 7.17: Real Analysis

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SUMMARY

The discussion focuses on proving Rudin's Theorem 7.17 from "Mathematical Analysis," which states that if a sequence of differentiable functions {fn} converges at a point x0 in the interval [a,b] and the derivatives {f'n} are continuous and converge uniformly, then the functions {fn} converge uniformly to a function f, and the derivative of f is the pointwise limit of {f'n}. The proof utilizes Theorem 7.16 and the Fundamental Theorem of Calculus as foundational tools for establishing the necessary convergence properties.

PREREQUISITES
  • Understanding of uniform convergence in function sequences
  • Familiarity with the Fundamental Theorem of Calculus
  • Knowledge of Theorem 7.16 from Rudin's "Mathematical Analysis"
  • Basic concepts of differentiability and continuity of functions
NEXT STEPS
  • Review the statement and proof of Theorem 7.16 in Rudin's "Mathematical Analysis"
  • Study the implications of uniform convergence on function sequences
  • Explore examples of sequences of functions that converge uniformly
  • Investigate the application of the Fundamental Theorem of Calculus in analysis
USEFUL FOR

Students and professionals in real analysis, particularly those studying advanced calculus and seeking to understand the implications of uniform convergence and differentiability in function sequences.

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i am asked to prove the remark Rudin made in theorem 7.17 in his Mathematical Analysis.

Suppose {fn} is a sequence of functions, differentiable on [a,b] such that {fn(x0)} converges for some x0 in [a,b]. Assume f'n (derivative of fn) is continuous for every n. Show if {f'n} converges uniformly, then {fn} converges uniformly to some function f and f'(x)=lim(n goes to inf) f'n(x). (x in [a,b])

Rudin's hint is to use theorem 7.16 and fundamental theorem of calculus.


Thanks for any help.
 
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Please follow the outline for posts given in the sticky -- in particular, you should (section 2) give the statement of theorem 7.16, since not everyone here has a copy of Rudin, and (section 3) tell us what you've done so far.
 

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