Sanity check about a linear programming problem
I’d say the program is always feasible because x = y = 0 is a solution.

Most pairs a, b give a unique solution. Only certain pairs don’t. 

Now it depends on the definition of “unbounded”. If we talk about the goal function, the minimum is always bounded by 0. If we talk about the points (x, y), they are unbounded if a &lt;= 0 or b &lt;= 0.