For high school math, please provide ideas for solving the problem first, and then answer 30

I've heard a champion of a simple learning network learn mathematics like this, he said that you must not ask the sea of questions, nor can you blindly learn high school mathematics is like the sea, there are too many knowledge points, each knowledge point can be extended, endless, if you have to understand all of them, it is unrealistic

The best way to learn is to know yourself and your opponent, and first understand what mathematics is tested in the college entrance examination.

Through the real math questions of each year to see what to test, the method is not to do the questions, only mark the knowledge points. What are the knowledge points tested in each question? To understand and then summarize, see that those knowledge points have a high chance of solving the question, so focus on these.

Those are secondary, just understand and be able to do the questions, those are relatively few, and they can't be ignored, and the content of the knowledge points must be understood.

Then get to know yourself.

Won't there? It's a hard question, and it's simple!

How do you know? Look at the wrong questions of your own papers, the same, don't correct the mistakes, mark the knowledge points first, mark the wrong questions yourself, mark the knowledge points involved in each topic, learn the knowledge points first, I don't understand the way the school teacher teaches the class, when I use the simple learning network, I use the point to listen to the class, find the knowledge points that will not be, only listen to that part of the content! After you understand, do the wrong questions yourself.

Doesn't it look right? And so it will be fine to repeat the cycle.

Third, understand the trend of mathematics in the college entrance examination.

The trend of the college entrance examination is different every year, so we should learn more about it, and see which ones have become the focus and those that are not important. Be aware before the exam.

For this kind of problem, first find the definition domain of variable x, and then find the maximum and minimum value (that is, the value range) according to the definition field.

The domain of this problem is x>=-1, and y>=-1 can be obtained by substituting the analytic expression of the function. It's a good idea to indicate the definition of the domain when answering the question.

When I was in high school, my teacher emphasized that I should learn to organize my own problems. Many people are like this: when the teacher talks about a problem you don't know on the blackboard, you can understand it below and think, "yes, that's it", but you may not be able to do it if you are asked to do it again.

Therefore, when the teacher leaves us time to tidy up after the lecture, he is not allowed to look at the blackboard, but has to tidy up by himself. If you look at the answer, it shows that you have no problem understanding mathematics, but the problem can only be that you don't understand it at all, but only listen to it. Only if you understand the meaning of the existence of each step (this is done to find out what steps are below, and what steps are introduced from this, and linking these steps is the complete solution method) can you really understand this problem, and on this basis, you should do more questions, and you will naturally know how to write steps when you encounter similar problems.

The second question can be calculated using the method of vectors.

The Cartesian coordinate system is established with point E as the origin, ed as the Z-axis, EC as the Y-axis, and the line parallel to BC at point E as the X-axis.

Then, the coordinates of each point are obtained, and the normal vectors corresponding to the two surfaces are obtained, and then the equation is established according to the vector coordinates and the angle is 60 degrees, and the required known is obtained.

Finally, the CA vector and the normal vector of the surface bcc1b1 are obtained according to the coordinates, and the sinusoidal value of the line-surface angle is obtained according to the vector coordinates.

Hope it helps!

To put it simply, when you get the test paper, the first step is to grab the score, starting from the first question, and finish the test questions that you can do completely; The second step is to pick up points and do those questions that you think are usually better at, or that you think are easier questions; The third step is to pick up points, according to your personal situation, first easy and then difficult to overcome the problem you think; The fourth step is to hit the score, and write the answers to the test questions such as filling in the blanks and judging that you don't think you can do, and if you are lucky, it is also good to hit one or two questions; The fifth step is to review, when all the test papers are completed, you must review them again, and correct the test questions that have been written incorrectly and have not remembered the answers for a while.

Under normal circumstances, the basic questions of the college entrance examination mathematics paper account for 70% of the score, the breadth questions account for 20% of the score, and the depth questions account for 10% of the score. The basic questions are relatively simple, as long as you can really master the basic knowledge in the books, you can get these points; The breadth question may not be difficult, but you must have a certain amount of knowledge, not only to learn the knowledge of the textbook, but also to do more questions on a regular basis, apply the knowledge in the textbook to the actual test questions, and combine the knowledge of algebra, geometry, functions and other knowledge to get these points; Deep questions are difficult problems, which not only assess a student's knowledge, but also assess the intelligence of a student's head, which is what top math students do, and it is recommended that ordinary students do not waste valuable time on difficult problems.

A normal student, if he wants to get 80-90 points in mathematics, in addition to being able to understand the knowledge taught by the teacher in class and learn the textbook knowledge well, he also has to do more math problems, not only the questions in the textbook and the questions assigned by the teacher, but also do more extracurricular questions.

Exam questions are nothing more than a modification of a certain type of question, if you have done all kinds of math problems, then the college entrance examination question is a modified form of a certain question you have done, that is, the teacher of the college entrance examination has changed a certain question you have done to the test paper, and it is strange that you will not do it.

In a word, if you want to get a high score, you can only do more questions.

Let me talk about my thoughts, first of all, assume that this five-digit number is composed of 1,1,2,3,4, the full arrangement is 5 4 3 2 1 120, and then subtract two 1 adjacents, five empty two rows 1 is 5 4 2 10 kinds, and the remaining three bits let 2, 3, 4 permutation is 3 2 1 6 kinds, so that the two 1s adjacent to each other is 10 6 60 kinds, so 120-60 60, replaced by 2, 1, 1, 2, 3, ,1, 2, 3, 1, 2, 3, 4. That's 60 times 4 240. Permutations and combinations of thinking and problem solving are ever-changing.

There are many ways, and I generally don't dare to use any special skills if the foundation is not solid. Just use simple classification and step-by-step, a lot of skills are not used well, either missed or repeated, you can use your own ideas to verify it!

Because 1 is less than or equal to a and less than or equal to 6

So 2a-1>a

1) Because a=2, 2a-1=3

f1(x) = f2(x), i.e. |x-2a+1|=|x-a|+1 When x is greater than or equal to 3, x-3 = x-2+1, there is no solution.

When x is less than or equal to 2, 3-x=2-x+1 is constant, and x 2 is his solution.

When 22, then g(x)=2a-x-1, the minimum is 2a-6, if a 2, then g(x)=a+1-x, the minimum is a-5 when a2 is true), g(x)=2a-1-x, at this time the minimum is 2a-7, therefore, when a>2, 2a-7-(2-a)=3a-9, if a>3, then the minimum is 2-a

If a 3, then the minimum is 2a-7

When a 2, a-5-(2-a)=2a-7 -3, so the minimum is a-5

In summary, when A2, the minimum is A-5

When 23, the minimum is 2-a

Find the average rate of change of y=sinx at a certain point, that is, find the derivative of y=sinx.

y'=(sinx)'=cosx

So k1=cos0 = 1, k2=cos(2 )<1, so choose a.

m(x-3) 2 -8m+8 0 (2 is squared).

Then it is discussed, when m 0 and m 0, is equal to 0.