Sustainable agriculture integrates three main goals, environmental health, economic profitability, and social and economic equity. These goals have been defined by a variety of philosophies, policies and practices, from the vision of farmers and consumers. Perspectives and approaches are very diverse, the following topics intend to to help understanding what sustainable agriculture is.
... it discriminates between three qualitatively different cases:
If the discriminant is zero, then there is a repeated solution x, and this solution is real. ...