The urgent plea for math lovers in the third year of junior high school 20

It's valuable that you can spend 1 hour a day studying math, and the key is to be consistent, and you will definitely get something over time. I'm also a math teacher, so I'll give you a few suggestions.

1.Don't do too many topics, don't study difficult and old problems, and keep them in line with the current textbooks, especially when choosing reference books, you should ask your instructor in this regard.

2.There are some very smart students, but the test scores are not very high, the reason is that their problem-solving habits are not good, and they are caused by rough branches. Learn to do it"Detailed"Three words.

In fact, the foundation should be solid, and the fine means to be bold and careful, and to make fewer low-level mistakes, whether it is a competition or a regular exam, we must try to avoid making low-level mistakes. There are few questions in the junior high school league exam, and the score of each question is high, which is particularly worthy of attention.

3.Learning should also combine work and rest, don't rush to achieve results, especially in mathematics, we can't surprise it. It is only by taking it step by step that it is possible to really learn well.

Overusing your brain will only do half the work. When it's time to relax, you have to relax and relax, there is still half a year before the national junior high school league, and you should be able to ensure that you have enough time to review.

4.We must have a peaceful mentality and establish a correct attitude towards success or failure. As long as you have worked hard, it is worth celebrating and happy if you succeed, and you don't have to be depressed if you fail, after all, everything cannot go smoothly in a person's life.

Also, you should have an instructor who will show you how to do it.

You can do less exercises, you can do some difficult problems that you have made with a sense of accomplishment, it doesn't matter if you can't do it, I suggest you buy 3 volumes and 1 review, this book is very good, and the comments are discussed at the back of the book, you can see for yourself. (I'm not here to advertise, it's up to you whether you buy it or not).

Compared with science courses such as mathematics and physics, liberal arts courses have the following characteristics:

1) Large amount of memory. Because of this characteristic, the learning methods you take in the liberal arts courses are significantly different from those in the sciences.

2) Understand abstraction. Unlike the understanding of science, which is more vivid and concrete, the understanding of liberal arts is a bit subtle and subtle.

Of course, each subject in the liberal arts has its own different characteristics, and here are only the common characteristics of them.

Liberal Arts Classroom Tips.

Class notes are indispensable.

Liberal arts courses have a lot of textual information, and what the teacher has said will be quickly forgotten, and even if you don't forget it at the time, you won't remember it deeply after a long time. If you don't take notes in class, the forgotten parts will disappear from your brain's knowledge base forever.

The role of note-taking in class is twofold: one is to make your thinking follow the teacher closely and increase the learning efficiency of the class; Second, it can be used as a supplement and memo to book knowledge, which can be used after class or during review. However, note-taking is not a journal, not to write down every sentence spoken by the teacher in class, but to write down important content, such as recording the knowledge structure system, thinking process, etc., and pay special attention to the content of the teacher's key prompts.

2) Listen to the class to be engaged, follow the teacher's thinking, and more importantly, be active in thinking.

This is when one's concentration is tested. If you don't pay attention, you are likely to get distracted by the teacher's beautiful story-like lectures.

In addition, under the guidance of the teacher, you should learn to think about the questions raised by the teacher. If a person in the text says something in the narrative, the teacher is likely to ask, what does that person mean by saying this? Then you have to think positively, not only to see every word in this sentence, but also to analyze the meaning of this sentence in connection with the previous part of the article.

In this way, your mind is alive during class, and your learning efficiency will be multiplied (and the same is true for studying science). So you will find that there are two people who are also very serious in class, why do one of them get good grades while the other has average grades? Here's why:

A class is full of thinking and often associates what is being learned with previous knowledge. In the other class, the thinking is only led by the teacher, learning and seeing, without their own thinking and analysis).

Learning mathematics is not only about hard work, but also about talent, and you have to find the right way.

I'm also in junior high school, and I like math very much, and I have a sloppy problem, and now I have overcome it, that is, every time I finish the test paper and do it again, I will find mistakes, I thought there were no questions that I couldn't do, but after the morning exam, I didn't have a few questions to do Sad!

That's what the teachers said.

I also liked math when I was in junior high school, although I don't like it anymore (hehe).

Then I'll give you some advice. However, there may be a repetition of what the teacher said above.

Hehe. First, don't deliberately choose difficult questions to do, and usually do more ordinary exercises, because difficult problems are an extension and synthesis of simple questions. If you practice the simple questions and have the basic skills well, then you can respond to all changes with the same.

Second, ask the teacher more. It's not about asking what you don't know, of course you don't know about it, and asking about what you feel bad about when you are writing the question and what you are stuck. The teacher can optimize your way of thinking, and can also tell you some simple ways to solve problems, don't think that the teacher tells you that it is meaningless.

In fact, some questions are really questions of knowledge, and if you have seen the same kind, you will do it, but if you haven't seen it, it's useless if you want to break your head.

Thematic Exercise 3. Especially when there are events. That works well. Because it can systematically summarize the ideas and methods of problem solving.

I can't think of it for a while. I thought of adding it again.

Study hard and make progress every day.

If math is fun, go "play", but avoid being complicated and impatient.

Play "do: 1. Solid.

2. Practice hard. 3. Adjustment.

4. Perseverance.

Doing Olympiad math problems is to be flexible, thoughtful, and think from multiple angles. You can't do it by rote. It is recommended that you rest more and think more, and the effect will be better.

Absolute value of x1-x2 = 3

So after the square is 9

x1 square + x2 squared - 2x1x2 = 9

Then it is written as (x1+x2) 2-4x1x2=9, i.e. m squared minus minus 4 equals 9

m is equal to plus or minus the root number 5

Solution: x -mx-1=-

According to: Vedic theorem: x1+x2=m, x1x2=-1(x1-x2) =(x1+x2) -4x1x2=m +4

Because |x1-x2|=3

So (|x1-x2|）²=9

So m +4 = 9

So m= 5

m= 5 satisfies the discriminant formula greater than 0

So m= 5

Analysis: (1) Use the sum of the inner and outer angles of the polygon.

The sum of the inner angles of the polygon = 180 degrees (n-2), and the sum of the outer angles of the polygon is always 360 degrees.

2) Find the inner angles, then know the outer angles, and then find the number of sides of a regular polygon surrounded by multiple regular pentagons through the outer angles. That is, if you know how many outer corners there are, you will know how many edges there are in the polygon you require, and then you will know how many regular pentagons there are in a circle.

Solution: 1. The sum of the internal angles of the regular pentagon = 180 degrees (5-2) = 540 degrees, and one internal angle = 540 5 = 108 degrees.

2. An inner angle of the inner polygon sought: 360 degrees 108 degrees 2 = 144 degrees An outer angle of the polygon sought: 180 degrees 144 degrees = 36 degrees 3.

360 degrees 36 degrees = 10 (strips).

So a total of 10 regular pentagons are needed, and 7 are needed.

The inverse proposition of the proposition "The three sides of the congruent triangle correspond to the congruent triangle" is the inverse proposition of "the three sides of the congruent triangle correspond to the equal" is the true digging proposition.

So you can't make the mistake of choosing D

I missed the exam.

The correct answer is a

Each judgment excites a proposition, whether true or false, there are original propositions, inverse lead limb propositions, negative propositions, and inverse negative propositions.

Isn't the proposition from high school?

From the graph, we can see that c= -3, -b (2a)=1, then y=ax 2-2ax-3

Bring (1,-4) into to get a-2a-3=-4 => a=1 ,b=-2

Then the original equation is 1-2x-3=3 => x=-5 2

Let y=a(x-h)*2+k Because the vertex coordinates are (1,-4), so y=a(x-1)*2-4, and because the parabola passes through the point (-1,0), so 0=a(-1-1)*2-4, so a=2, so y=2(x-1)*2-4, when y=3, x1=7 root number 2 2+1, x2=-7 root number 2 2+1

Vertex coordinates (1,-4) to the left of the intersection of the y-axis (0,-3) If the equation is ax2 (2 is squared) + bx + c=0 you should know how to solve it. The difference between ax2 (2 is squared) + bx + c = 0 and c in ax2 (2 is squared) + bx + c = 3 is 3

Personally, I think.