Relationships are usually used to describe the relationship between two or more variables, which can be equality, inequality, function and so on. The establishment of relational expression is helpful to understand and study the relationship between mathematical objects and to solve practical problems, such as modeling in physics, chemistry and other fields. There are many forms of relationship, such as linear relationship, quadratic relationship, logarithmic relationship and so on.
Relationship is widely used in mathematics and is an important tool for mathematical analysis and modeling. Mathematical problems can be deduced, proved and solved through relational expressions, so as to better understand and master mathematical knowledge and skills.