Please help with these problems. I have been stuck and my prof is unavailable this weekend

Given f(x, y) =4+ x' -3xy + y' . Find all relative extrema and saddle points. Show all steps that verify your solutions.You are constructing a 480 cubic feet box. The bottom of the container costs $5 per square foot to construct whereas the top and sides cost $3 per square foot to construct. Use Lagrange multipliers to find the minimum cost. Show work. Given the temperature distribution function T(x, y) = x2 - x + 2y2. a) Find all relative extrema points of T(x, y) = x2 - x + 2y2. Show all steps to verify your solution. b) Use the method of Lagrange Multipliers to find the maximum and minimum of T(x, y) = x2 - x + 2y subject to the constraint x2 + y2 = 1. Show all work to justify your solutions