Feasible Regions

Introduction to Feasible Regions

  • Feasible regions are defined as the set of all possible solutions to a system of linear inequalities that satisfy all the constraints in a linear programming problem.
  • Geometrically, a feasible region can be visualized on a graph as the common area shared by all inequalities.
  • Unbounded feasible regions extend indefinitely, while bounded feasible regions are confined within a certain region.

Characteristics of Feasible Regions

  • The vertices or corner points of the feasible region often contain the optimal solution for a linear programming problem.
  • Feasible regions can either be empty (when no solutions satisfy all constraints) or non-empty (when there exist solutions that satisfy all constraints).
  • The solution to a linear programming problem can be unique or there can be multiple optimal solutions.

Drawing Feasible Regions

  • To draw feasible regions, start by graphing each linear inequality on the same graph. Each inequality divides the graph into two halves.
  • Identify which half of the graph satisfies each inequality and find the overlap of all these areas. This overlap represents the feasible region.
  • Label the vertices of the feasible region for further analysis.

Solving Problems with Feasible Regions

  • Linear programming problems often require finding the maximum or minimum value of an objective function within the feasible region.
  • Plot the objective function on the same graph as the feasible region. The optimal solution is usually one of the vertices of the feasible region.
  • If the objective function line passes through the feasible region, then there may be multiple optimal solutions. If it only touches the feasible region at a single vertex, then there is a unique optimal solution.
  • Solving linear programming problems often involves iterative methods, such as the Simplex method or graphical analysis.