How can I calculate the differentiation of qi if I have the sum of n qi
Maybe this:
W1 = (\[Alpha] - (Sum[Subscript[q, j], {j, 1, n}]) - Subscript[w, i]) Subscript[q, i] - t Subscript[e, i] - (\[Gamma]/2) (Subscript[a, i])^2 - K; Simplify[D[W1, Subscript[q, i]], Element[i, Integers] && 1 <= i <= n]
Thank you very much.