Linear Programming

作者:
johnmayhk
Suppose the polygon ABCDE is the feasible region for certain constraints. Click the check boxes for different objective functions. Drag the point to translate the corresponding line. See the changes of values of different objective functions. With the help of the lines, or otherwise, find the maximum and minimum values of objective functions.

Why the movement of the red line is restricted, i.e. it is not allowed to translate to any position?