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

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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
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...

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