I am attempting to design a linear program where I optimize the amount of money I make by selling good $A$. Selling units of $A$ below a threshold $t$ results in an income of $a$ dollars per unit of $A$ and selling quantities greater than that threshold $t$ results in an income of $b$ dollars per unit.
How might I model this as a linear objective function?
The situation I'm trying to model is that every day I produce an expected amount of resource $A$ with the amounts known in advance. I can either choose to sell resource $A$ or store it for later selling, but I have a limited capacity of storage for the resource.