What’s going on?
Notice: feasible sets completely different for primal and dual, but nonetheless an important relation between them.
Duality theorem says that in the competition between the grocer and the druggist the result is always a tie.
Optimal solution to primal tells purchaser what to do.
Optimal solution to dual fixes the natural prices at which economy should run.
The diet x and vitamin prices y are optimal when
- grocer sells zero of any food that is priced above its vitamin equivalent.
- druggist charges 0 for any vitamin that is oversupplied in the diet.