This question further requires you to understand notational issues as they relate to partial derivatives. For this problem, consider the expression: Ij = Et w 0; for j = 1, ..., 4 where the w, are the variables. 812 aIs (D) Bags (c) aly for r = J Billers all forr * j What is the proper expression for (a) What is the proper expression for (b) V What is the proper expression for (c) A What is the proper expression for (d) ei ei 0 es er