Hi All,

I have a concave problem that I have checked concavity from simulation, and I wonder if someone is familiar with how to get the first derivative for the function encompassing summation.

Obj(alpha) = (alpha/k) \sum_{n=k+1}^{ceil( (k/2)*(1+1/alpha) )} log2(1 + fn(n))

fn(n) is a function of alpha since the summation bound has alpha. assume any concave function for fn(n), how to differentiate Obj(alpha) w.r.t. alpha

alpha is a scalar