# Integral with some symmetries

1. Apr 26, 2009

### the_phoenix

1. The problem statement, all variables and given/known data

Hi, i need to integrate a function which has a very nice structure. however, in case i cannot do the same, i would need a bound on the value of the integral. The problem is basically a minmization problem with n parameters. Please follow the link to acquaint your self with the problem.
http://img522.imageshack.us/img522/7894/equations640x480.gif [Broken]

2. Relevant equations

http://img522.imageshack.us/img522/7894/equations640x480.gif [Broken]
here, d_i and theta_i are the distances and angles of point (x,y) from (xi,yi)

3. The attempt at a solution
My attempt is as follows:
First of al, i could not directly integrate the function, so i tried to find a bound on it. I used the mod of the function (extension of triangle inequality) on the denominator to eliminate the sine squared in the denominator.
Upon doing that i tried to split the denominator through chebyshev sum inequality but didnt get anywhere.

I hope you can give me some insights into either solving the integral or getting a bound on its value.

thanks and regards

Last edited by a moderator: May 4, 2017
2. Apr 30, 2009

### benorin

Would you elaborate on the geometry of the sum, specifically, where does the $$d_{i}^{-2}d_{j}^{-2}\sin^2 (\theta_{i}-\theta_{j})$$ term come from?