High school math problems are estimated not to be available to the average person

This question is a bit interesting, combining a sequence of numbers with analytic geometry.

Since you can't understand it in the first place, I'll explain it to you.

|aiai+1|=ai+1 - ai = 2i-1 and a1=-1 4, this is a series of numbers, which can be used to find the general term formula an by accumulation.

an=n^2-2n+3/4

Then using the fact that the triangle is a regular triangle, you can find the coordinates of the bn.

Abscissa bn(x)=[an+a(n+1)] 2=n 2-n+1 4 ordinate bn(y)=(a(n+1)-an)* 3 2 = 3*(n-1 2).

By subtracting the parameter n from the abscissa and ordinate formulas, we get the equation of y 2=3x which is the parabola c. Proven.

The following answer is to quote the brother above.

Solution: The coordinates of B1 are (1 4, 3 2).

ob1|=√13/4

From the symmetry property, the equation for l is y=(2 3+ 13 8)l

Proof: From the parabolic properties, EM-EN is perpendicular to the x-axis and EF is on the x-axis.

Therefore, the included angle is always 90 degrees.

Summary. Hello, please send out the complete questions Ha high school math problems will not.

Hello, please send out the full question

sn+1 2-sn 2=8 n, where a1=1 is found sn, and sn+1 is a whole.

You can take a ** ha.

This one, right? This is when n is greater than or equal to 2.

When verifying n=1, just synthesize it.

Summary. Hello, I am the co-teacher of Ask a question, Mr. Kodaka, who is good at junior high school and university education, and has been engaged in the education industry for 10 years now, and I am happy to serve you. Please wait patiently, about 5 minutes.

Hello to you, I am the co-teacher of the question, Mr. Xiao Kai Potato Gao, who is good at junior high school and college education, and has been engaged in the education industry for 10 years, and I am very happy to serve you. Please wait patiently, about 5 minutes.

The first question. Question 5 and 6.

I can only answer one oh dear.

Question 5. Question 5 (1) 4 teams round robin game, then the mold roll is from the 4 New Year's Day shouts Yu Su infiltration stove to draw 2 elements 2 c (4,2) = 2 (4 3) (2 1) = 12 (2) 2 a (2, 2) = 2 2 1 = 4 (3) only 1 game, then the total is 12 + 4 + 1 = 17

Question 5 (1) 4 teams round robin game, then the mold roll is from the 4 New Year's Day shouts Yu Su infiltration stove to draw 2 elements 2 c (4,2) = 2 (4 3) (2 1) = 12 (2) 2 a (2, 2) = 2 2 1 = 4 (3) only 1 game, then the total is 12 + 4 + 1 = 17

Everything about high school math was solved by humans 100 years ago. In other words, what high school students are learning now is more than 100 years ago. For example, the concept of imaginary numbers is never as simple as square equals minus one, and I know a lot of teachers start with square equals minus, and then they start working on problems.

The origin of imaginary numbers, its practical significance, its beauty, are not explained.

Sad, hello, I am a Ph.D. student at Tsinghua University, I have been a tutor for 6 years since I started to do a stall in Zhuzhu High School, during the tutoring of students, I wrote a book "2019 Yati Volume and the Best School College Entrance Examination Proposition Trend", the book elaborates on the topic of the college entrance examination questions, this book not only summarizes a large number of questions and skills, but also ** the 2019 college entrance examination. If you can't find a review during the sprint phase, this book will be very helpful for you.

If high school math is not difficult, it is definitely a very small number of people, because the vast majority of people can be said to be difficult. But this is not to say that it is difficult to get a high score, as long as the IQ is normal, you can still get a high score within your ability through scientific practice! What is the hardest part of the college entrance examination now?

I think a lot of you have a couple of places where you can think of one is analytic geometry, one is derivatives, one is functions, and maybe some solid geometry.

It can be said that in the entire college entrance examination test questions, these sections must have the highest score loss rate! So how can you do well in high school? I have to do the subject study questions, but you have to do them, and I will do them, my positioning method is to "establish a knowledge list, list them one by one, and solve the problem" The specific method is to list the analysis of the examination room, and look for the corresponding problem to solve, until it is solved, it must be not enough, and it must be solved clearly to do the next project.

Instead of casting a net in a large area and reaping nothing!

For this problem, in fact, it should be divided into different situations to analyze, for example, some students may have just entered the first year of high school, then for some math problems, because they have not learned, so they will not do it, which is also normal, but if the first stage of high school is about to be completed, there are many math problems that will not be done, and these topics have been taught by the teacher, then it should not be, after the first year of high school, the problems taught by the teacher, the students themselves will not be able to do it, then it is not normal. In response to this question, Mr. Xiaojiang would like to share a few personal views.

Clause. First, the students themselves will not do the topics they have learned, so it is abnormal Some high school students do not listen carefully to the teacher's lectures when they are in class, and the topics that the teacher has talked about, they will not do it after class, mainly because they are distracted in class, so they have not learned the relevant knowledge points, and there is no timely review after class, so they forget the knowledge they have learned in class, so they will naturally not do some math problems.

Some high school students slack off in their freshman year and do not listen carefully to the lectures when they take math classes, resulting in them not even being able to grasp some basic math knowledge points, so they can't solve many math problems, so this situation is an abnormal situation. For first-year high school students, if they don't grasp the knowledge they have learned well, and they don't know how to do many topics, then they will directly expose a problem, that is, they don't listen carefully to the teacher's lectures in class, and they don't have to study hard.

Clause. 2. Know how to find out what your problems areIf most of the math problems you have learned before will not be solved, then students should find out their own learning problems, for example, to see if they are not concentrating in class, whether they are distracted during class, or whether it is because they have not mastered the correct learning methods.

As a result, I can't solve the relevant math problems.

Only by finding out their own learning problems, can they prescribe the right medicine and correct it, although some high school students listen carefully to the teacher's lectures during class, but they do not review in time when they get out of class, and the learning efficiency is low, then there will not be too good learning results.

Clause. Third, the key is to cultivate their interest in the subject of mathematicsThe knowledge of mathematics is generally relatively boring and boring, and is not as emotional as Chinese and English subjects, so students need to know how to cultivate their interest in mathematics and find the fun in the process of learning mathematics, so that they can fall in love with learning mathematics, and want to cultivate their interest in mathematics There is a good way. That is, you can read some interesting mathematics books, which can stimulate students' interest in learning mathematics and help students establish good mathematical thinking skills.

Students can also improve their math scores as a result, and when they encounter some difficult math problems, they will naturally be able to solve them.

So what do you think about this issue?

High school mathematics is not as difficult as junior high school mathematics, and the first year of high school may not have adapted to it, so it is normal that some questions will not be done, we should do more exercises, consolidate subject knowledge, and really do not need to find teachers for tutoring.

This is normal, because you can't be very proficient in every subject, and there will definitely be problems that you can't do.

Abnormal. You can do the questions to show that the teacher has already talked about it, but you still have a lot of words that you can't do, it's your own problem.

Hello, how to learn mathematics well in the first year of high school, read textbooks well, learn to research, you should start from high school, enhance your awareness of starting from textbooks to conduct research. You can take each theorem and each example problem as an exercise, carefully re-prove and re-solve it, and add some annotations appropriately, especially through the explanation and analysis of typical example problems. It is important to develop good listening habits in the first year of high school mathematics classroom teaching.

Mathematics in the first year of high school is not taught by the teacher, but under the guidance of the teacher, it is obtained by one's own active thinking.

It is recommended to make a plan for your own further education, which can plan the most favorable plan for further education according to your grades to help you get admitted to the ideal university.

High school mathematics has a large amount of knowledge and is difficult to understand, and if you don't pay attention to review and consolidate in time, then there will inevitably be many questions that you can't do.

Is it normal that there are a lot of questions in high school math that you can't do?

Solution: 1) The circle does not include the boundaries of the circle.

Therefore, the required probability satisfies x +y <18

There are combinations that meet the requirements.

There are 10 types in total. And in all cases, there are 6x6=36 types.

Probability = 10 36 = 5 18

2）mx²+2ny²=1

a²=1/m

b²=1/(2n)

Its focus is on the x-axis.

then a >b

m<2n

There are combinations (m, n) that meet the conditions.

There are 25 types in total. There are 6x6 = 36 types in total.

Therefore, the probability is 25 36 = 25 36