is differentiable and 
for all 
.
,
.
such that 
Edit: Proposed by Marian Vasile (congrats!).
.
be a continuous function defined on ![$[0,1]$](http://latex.artofproblemsolving.com/e/8/6/e861e10e1c19918756b9c8b7717684593c63aeb8.png)
with 
and 
.
to be the projection of point 
on the x-axis. Prove that there exist points 
such that 
is a square.
![$f : [0,1] \longrightarrow \mathbb{R}$](http://latex.artofproblemsolving.com/9/a/4/9a4b7997c35990f839742d29866122791ade8b7c.png)
is differentiable with 
.
for all ![$x \in [0,1]$](http://latex.artofproblemsolving.com/d/3/4/d3423a3200d0ad7660fc4265d59d5598a53d551d.png)
,
for all 
.
increasing with
?
?
Y by Exponent11
hi. my aops whenever i go 2 the website the website is like way to big and i cant access anything? i am on via an ingognito window but its kind of inconvenient not sure if its just my laptop or the website. i cant recreat it on any other device? plz help [/resolved]
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This post has been edited 1 time. Last edited by JohannIsBach, Apr 26, 2025, 8:39 PM
