1. When it is applied to large-scale production such as construction, breeding, afforestation and product manufacturing, the relationship between profit and investment can generally be expressed by quadratic function. Business managers often predict the prospects of enterprise development and project development based on this knowledge. They can predict the future benefits of enterprises through the quadratic function relationship between investment and profit, so as to judge whether the economic benefits of enterprises have been improved, whether enterprises are in danger of being merged, and whether the project has development prospects.

2. When applied to production and construction, many practical problems related to optimization design can usually be solved by applying mean inequality;

3. When shopping, renting a car or staying in a hotel, operators often provide two or more payment schemes or preferential measures for publicity, promotion or other purposes. At this time, you should think twice before you act, dig deep into your mathematics knowledge and make a wise choice.