The math problems that children have done in junior high school will not be done after a while. Some questions are difficult, but they are forgotten after a while. Especially some written questions, there will be some psychological dependence. I feel that I don't want to use my brain after writing this question. Some children with good memories may be able to remember these steps. Some children may be unable to write now. The main reason is that there are fewer questions to do and more mistakes to correct. If you understand it in time, especially if you do more math problems, you will find the feeling. Only a small part of mathematics depends on memory, and most of it is to exercise your independent thinking ability, so it is no problem to do this math.
What should I do if I can't do math problems in high school? But if I am reminded, I must practice math more. Many questions are the same, and the steps to solve them are similar. Even if I don't pass the exam, I can still get the process score, and I will try my best to maximize the score in the exam.
You can't do the last math problem in high school, so can I. You should practice more.
I have done high school math problems, which are easy to forget. What shall we do? I think reflection and summary are not enough. When I was in high school, our math teacher paid great attention to our summary and reflection on knowledge points and questions. I was disgusted at the time, but now I think it makes sense. The questions I have done are unlikely to appear again in the exam, so they are useless to the group. It is important to sum up the methods and ideas of solving problems, so that an exercise can be established. I hope it helps you.
Answering skills in senior high school math exam. For mathematics, solid geometry occupies a large proportion, and the solutions are as follows:
1. Strategies to show the relationship between parallel position and vertical position:
(1) Judging from the nature of the known idea and the idea to prove it, that is, combining analytical method and comprehensive method to find the idea to prove the problem.
(2) Adding auxiliary lines (or faces) according to the nature of problem setting conditions is one of the commonly used methods.
(3) The three perpendicular theorem and its inverse theorem are used most frequently in the college entrance examination questions, so it should be given priority to prove that the straight line is vertical.
2. Calculation methods and skills of spatial angle:
Main steps: one post, two certificates and three calculations; If you use vectors, it is a proof and two calculations.
(1) Angle formed by two straight lines on different planes ① Translation method: ② Complement method: ③ Vector method:
(2) The angle formed by a straight line and a plane
(1) To calculate the angle between a straight line and a plane, the key is to make a vertical line, find a projection and convert it into the same triangle for calculation, or use a vector for calculation.
② Calculate by formula.
(3) dihedral angle
① Practice of plane angle: (1) Definition method; (2) Three vertical theorems and their inverse theorem methods; (3) Vertical plane method.
(2) Calculation method of plane angle:
(i) Find the plane angle, and then calculate it by triangle (solving triangle) or by vector; (ii) Projection area method; (3) Vector included angle formula.
3. Calculation methods and skills of spatial distance:
(1) Find the distance from a point to a straight line: the perpendicular of a point to a straight line is often determined by using the three perpendicular theorem, and then it is solved in the related triangle, or the distance from a point to a straight line is found by using the method of equal area.
(2) Find the distance between two straight lines on different planes: generally, find the common vertical line first, and then find the length of the segment of the common vertical line. If you can't do the common perpendicular directly, you can convert it into a line-plane distance solution (in this case, you don't need the college entrance examination).
(3) Find the distance from a point to a plane: generally, find (or make) a plane perpendicular to the known plane passing through the point, make a vertical line through the plane of the point by using the properties of the vertical plane, and then calculate; You can also use the "triangular pyramid volume method" to directly find the distance; Sometimes it is difficult to find the distance of a known point directly, we can convert the distance from a point to a plane into the distance from a straight line to a plane, and then "transfer" it to another point, and then we can find the distance from a point to a plane. Finding the distance from a straight line to a plane and the distance from a plane to a plane are generally converted into the distance from a point to a plane.
4. Memorize some commonly used small conclusions, such as: the volume formula of regular tetrahedron is; Area projection formula; "vertical and horizontal relations"; Minimum angle theorem. Finding out that the projection of the apex of the pyramid at the bottom is the condition of the inner heart, outer heart and vertical center of the bottom, which may be the premise of answering some questions quickly.
5. For the folding of plane graphics and the unfolding of three-dimensional graphics, we should pay attention to the "invariance" and "invariance" of geometric elements before and after folding.
6. For problems related to the ball, we can only apply the "old method" to find the radius of the ball.
7. Solid geometry reading questions:
(1) Find out what the geometric shape is, regular, irregular, combination, etc.
(2) Defining the structural features of geometry. What is the relationship between plane, straight line and line (parallel, vertical, equal)?
(3) Pay attention to what are vertical planes, vertical lines, parallel lines and parallel lines.
8. The problem-solving procedure is divided into four processes: ① Find out the problem. In other words, what is the known "verification question"? What are the conditions? What is the unknown? What is the conclusion? This is what we often say. (2) make a plan. Find out the direct or indirect connection between the known and the unknown. On the basis of understanding the meaning of the problem, we can capture useful information from it, extract relevant information from the memory network in time, and then combine the two groups of information resources logically and effectively, thus conceiving a successful scheme. Is what we often call thinking. ③ Implementation plan. Use concise, accurate and orderly mathematical language and symbols to express the idea of solving problems and verify the rationality of solving problems. This is what we call the answer. 4 review. Verify the conclusions and summarize the methods to solve the problems.
Let's do high school math problems! $= 1/2。 According to the nature of vectors, if two vectors (m = (x, y) and n = (x', y') are parallel, there is: xy'-x'y=0. Accordingly, to make A and B parallel, only (1+2 $) * 4-(2-3 $) * 6544.
Ask how to do high school math problems. This question is too big for anyone to answer!
There are several books about how to solve problems for you to read:
Paulia's How to Solve Problems
Follow the "problem-solving research"
Luo Zengru's introduction to solving mathematical problems.
There is an electronic version online. Have a good look, I hope it will help you.
High school math problem! Come on! F' (x) = 2x-a-a/(x-1) = x (2x-2-a)/(x-1) Function field x >: 1 order f' (x) > 0x > (a+2)/2, the function only has the interval of monotonically increasing x >；; (a+2)/2
It is known that Z is an imaginary number, the reciprocal of Z +2 multiplied by the square of Z is a real number, and ARG (3-Z) = π/4, so find Z..
Solution: let z = x+yi (y ≠ 0) (the inverse of z is -z).
z？ -2z=(x？ +2xyi-y？ )-2(x+yi)=x？ -2x-y？ +2(xy-2y)i is a real number, so xy-2y=y(x-2)=0, y≠0, so x=2.
∴z=2+yi,3-z=3-(2+yi)= 1-yi
arg(3-z)= arg( 1-yi)= arctan(-y)=π/4； So -y=tan(π/4)= 1, that is, y=- 1.
So z = 2-i.