I. Explanation:

The root number two must be a number between 1 and 2, and then calculate the square size of 1.5, which is a process of finding the approximate solution of equation x 2 = 2 by dichotomy.

Second, the root number:

1 and the root number 2 are about equal to 1.4 14, which are mathematical symbols, and the root number is a symbol used to represent the root operation of a number or an algebraic expression.

2. if a? =b, then a is the n-th root of b or a is the 1/n power of b.

3. The nth handwritten and printed character is represented by, and the number or algebraic expression of the square root is written in the area surrounded by the left side of the symbol and the right side of a horizontal part above the symbol, which cannot be crossed.

Third, the history of the root number:

1. In modern times, we are used to using radical symbols (such as √). ), and feel simple and convenient.

In ancient times, Egyptians used the symbol ┌ to represent the square root. When Indians are squaring, how many people are squaring? Write ka in front. Used by Arabs. 1840 or so, the Germans used the dot "."to represent the square root, two dots "..." to represent the square root of the fourth degree, and three dots "..."

3. It was not until17th century that the French mathematician Descartes (1596 ~ 1650) first used the radical sign "√ ~". In a book, Descartes wrote: "If you want to find the square root of n, write it;" If you want to find the cube root of n, just write. "

4. The cube root symbol appeared very late. It was not until18th century that we saw the use of symbols in books, such as the cubic root of 25. Later, such as √ ~, radical symbols gradually began to be used.

How to learn mathematics well;

First, cultivate interest in learning:

1. Have a strong interest in learning. Try to cultivate your interest in mathematics. Over time, you will find that math is not that difficult. Try to read more cartoons and books about mathematics, which can cultivate your interest in mathematics. ?

2. Find a person who is super good at learning and ranks in the top 3 in the class as an "enemy". Try to think of him as your enemy. Think about why you can't surpass him and why you can't study as well as him. Try to anger yourself and try to surpass him. Sometimes success requires the help of the enemy.

Second, study hard:

1, review before class, try to read the original words in the book, draw them in marks if you don't understand, listen carefully in class, understand if you don't understand, or raise your hand and ask the teacher, who will explain them to you.

2. Listen carefully in class and review carefully after class. Follow the teacher's thinking in class, see where the teacher says, ask if you don't understand after class, raise your hand actively in class, develop the good habit of listening to classes and improve efficiency.