Feasible Solution Set

Corner Point OR Vertex:
A point of a solution region where two of its boundary lines intersect is called a corner point or the vertex of the solution region.

Problem Constraint:
In a certain problem from everyday life each linear inequality concerning the problem is called the problem constraint.

Non – Negative Constraint OR Decision Variables:
The variables used in the system of linear inequalities relating to the problems of everyday life are non–negative and are called non–negative constraints or decision variables.

Feasible Region:
The solution region of an inequality restricted to the first quadrant is called the feasible region. In this case both x and y are always non–negative, i.e. {\text{x}} \geqslant 0, {\text{y}} \geqslant 0.

Feasible Solution:
Each point of the feasible region is called the feasible solution of the system of linear inequalities.

Feasible Solution Set:
A set consisting of all the feasible solutions of the system of linear inequalities is called the feasible solution set.

Convex Region:
If the line segment joining any two points of a certain region lies entirely within the region, then such a region is called the convex region, as shown in the figure.