![](/files/happy5.png)
Conjecture There exists a real positive
, such that for any
and any
where
for
and
, the following holds:
![$ c $](/files/tex/dccee841f3f498c2c58fa6ae1c1403c5a88c5b8d.png)
![$ n\in\mathbb{N} $](/files/tex/6ab85c2397977f785c3874c9665c18848ddef70d.png)
![$ z_i\in\mathbb{C} $](/files/tex/74292adfd82ef7e1d3d634a852bd9b90bc17b743.png)
![$ |z_i|\le 1 $](/files/tex/d830a710a3211821ddf6f9632cf0af362a02942c.png)
![$ 1\le i\le n $](/files/tex/3282f6c94ba622752c04e64c4bd697299e8219ff.png)
![$ \~z:=\frac{1}{n}\sum^n_{k=1}z_k $](/files/tex/c58de6dddeab0f501f20f8cb044babef37a4007f.png)
![$$\left|\prod^n_{k=1}z_k - \~z^n\right| \le c\cdot\sum^n_{k=1}|z_k-\~z|^2$$](/files/tex/524ebfaf6165fdbca63d19be83aa1db754af050e.png)
Bibliography
* indicates original appearance(s) of problem.
Recomm. for undergrads: yes |
Posted | by: | feanor |
on: | April 7th, 2010 |
Solved by: | fedorpetrov here in comments |