f(x) = k * (x^2 -2(a1)x + (a1)^2 + x^2 -2(a2)x + (a2)^2 + ... + x^2 -2(an)x + (an)^2) / n
      = k (x^2 - (2/n)(a1 + a2 + ... + an)x + ((a1)^2 + (a2)^2 + ... + (an)^2)/n

so we have
f'(x) = k(2x - (2/n)(a1 + a2 + ... + an))

question: what is k?
(explaining from previus post)

Edited by author 05.05.2016 14:53

Edited by author 05.05.2016 14:54