# Lagrangian Duality

Weak duality theorem states that the objective function value for any feasible solution of the Lagrangian dual (minimization problem) is an upper bound for the value of the objective function of any feasible solution to the original dual LP(maximization problem). We know that both problems are feasible. If the Lagrangian dual is bounded so is the dual LP. However, what can be said if the optimum of the Lagrangian dual is unbounded regarding the fact that the dual LP is feasible?

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