How to learn the quadratic root of mathematics?

I'm glad to see you say that you like math very much.

The first thing I want to say is to have confidence. As long as you are interested, you will learn well. It's just a matter of method.

That's what I thought when I first came into contact with the radical formula. From elementary school to junior high school, I learned nothing more than four operations: addition, subtraction, multiplication and division. At present, the root sign is the fifth operation method. Like addition, subtraction, multiplication and division, the radical sign is also an operation, but this operation has new rules.

If you study mathematics, from the point of view of examination, you should learn two things well: first, basic concepts and formulas, and second, questions. Let's talk about the basic concepts first, and then talk about some problems.

Learn the concept properly, so that you will be confident when you do the problem, because when you encounter a difficult problem, you will know that everything is here, and you will not be afraid of other strange tricks.

Rule 1: positive numbers and 0 can only open the root sign, and negative numbers can't be opened temporarily (negative numbers can also be opened temporarily in high school). Note that all positive numbers, including integers and decimals, etc.

Rule 2: What is the result of a specific number, such as 3, except some special numbers? Can't be accurately expressed by numbers with decimals. It's not like+-×, so you can't expect to write the result of the root number 3 by hand. The result on the calculator is only an approximation. So the result of the root number 3 is the root number 3, which should be expressed by the root number. This should be understood. The root number 3 represents a number whose value is about 1.732.

Rule 3: The operations of square root and square are a pair of inverse operations, so they are always inextricably linked. The square operation is only a multiplication operation, not a new operation. The opposite operation is that if:

A 2 = b< =>A = radical B. (Here a & gt=0, and the double arrows indicate that the left and right sides can be pushed out of each other.)

Quadratic radical operation is the inverse operation of square. You can write a= radical B from A 2 = B, or A 2 = B from a= radical B.

In this way, with this relationship, you can write the relationship between A and B at will. All relationships are derived from this basic relationship, and other derived problems can be solved by grasping the source.

Question type:

It is nothing more than two basic definitions, that is, the quadratic root can only be used for non-negative root numbers, and it and the square are reciprocal operations. Others are common mathematical skills.

It should be noted here that the result of the quadratic root sign is always non-negative, but the object of the square operation can be any number (because there is no need to add, subtract, multiply and divide the logarithm, except that the denominator of the division operation cannot be 0). So above, if A is negative and a 2 = b, then a=- radical B. For example, (-2) 2 = 4, then -2=- radical 4. So for general A, the relationship is:

A 2 = b< =>A =+/-radical b

In this way, when learning mathematics, you can give some simple examples to prove whether your ideas are correct. But remember:

To prove a conclusion wrong, give an example.

But to prove that a conclusion is correct, it must be able to prove that the conclusion is correct in all cases. If you can't see a specific example is correct, it means that a general conclusion is correct, otherwise you will make a mistake.

For example, if 2 is multiplied by 1=2 and 2 is divided by 1=2, we can't just say that A× B = A÷B