Proving the Existence of a Fixed Point using the Intermediate Value Theorem

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The discussion focuses on proving the existence of a fixed point using the Intermediate Value Theorem (IVT) for a continuous function f mapping [0, 1] to itself. One participant successfully demonstrates this by defining a new function g(x) = f(x) - x, although they seek a simpler proof. The conversation highlights that this example is commonly used in lessons on the IVT, while acknowledging that more complex proofs exist, such as Brouwer's fixed point theorem. The participants express appreciation for the insights shared. Overall, the fixed point existence is affirmed through the application of the IVT.
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Homework Statement


Let f : [0; 1] -> [0; 1] be continuous on [0; 1]. Prove that there exists C \epsilon [0; 1] such
that f(c) = c.

Homework Equations


The Attempt at a Solution



I've manage to prove this by having an extra cont. function g(x)=f(x)-x .. But I am looking for easier proof
 
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Sorry, that's the easiest proof available :smile:
 
micromass said:
Sorry, that's the easiest proof available :smile:

Is it one of the common proof and example when they conduct lesson on IVT?
 
Yes, this is one of the common examples when discussing the IVT. There are other proofs however, but these are quite complicated (see Brouwers fixed point theorem)
 
Thank you! Greatly appreciate ur time =D
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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