5
$\begingroup$

I am struggling to find an answer of the following series

$\sum_{i=1}^n \frac{1}{1+\exp(a_i+b_ix)}$

Any suggestion?

  • 0
    You won't be able to. For an example, let all the $b_i$ be zero. Compare $a_1=a_2=5$ to $a_1=0, a_2=10$ These are not equal, but your expression cannot tell them apart.2012-10-05

0 Answers 0