What are the properties of cost function?

Properties of Cost Functions:

Some similarities are here with consumer theory. Such similarities are actually exact while one compares the cost function along with the expenditure function. In fact, consider their definitions by given as:

The two optimization problems are identical mathematically. Therefore, for every theorem we proved about expenditure functions, where an equivalent theorem for cost functions is demonstrates. These results state here, but do not require proving them. Their proofs are known to those provided for the expenditure function.