Typically, use:

1. Definition of "molecular rationalization": For a fraction, if the molecule is an algebraic expression composed of irrational expressions, the process of transforming it into rational expressions by some methods is called molecular rationalization.

2. "Denominator is rational number": also known as "denominator of rational number", it refers to the process of transforming irrational numbers in quadratic roots into rational numbers, that is, removing the root sign in the denominator.

3. Relationship between "molecule is physico-chemical" and "denominator is physico-chemical": "molecule is physico-chemical" means the number of components. Because numerator is a rational number, "denominator is a rational number" is used in most cases. But when doing problems, it is sometimes easier to calculate molecules in a rational way.

Extended data:

Molecules have physical and chemical functions.

1, molecular rationalization can achieve some size comparisons that are difficult to carry out in the standard form by unifying molecules, and sometimes it can greatly simplify some product operations.

2. High school mathematics uses definitions to prove monotonicity.

3. Calculation of the limit of calculus.

Compare the sizes of √7 -√6 and √6 -√5.

Take molecular rationalization as an example.

[(√7 -√6)*(√7 +√6)]/(√7+√6)

= 1/(√7 +√6) ( 1)

[(√6 -√5)*(√6 +√5)]/(√6+√5)

= 1/(√6 +√5) (2)

Now (1)(2) two molecules are the same, and the denominator is (1) > (2).

So √ 7-√ 6