Basic strategies for solving multiple-choice questions
Multiple choice questions mainly examine the understanding of basic knowledge, the proficiency of basic skills, the accuracy of basic calculation, the application of basic methods, the rigor of considering problems and the speed of solving problems.
The basic strategy of answering multiple-choice questions is to make full use of the information provided by topic setting and branch selection to make judgments. Generally speaking, if you can make a qualitative judgment, you won't use complicated quantitative calculation; If we can use special numerical values to judge, we don't need to use conventional solutions; If you can use indirect solutions, you don't have to use direct solutions; We should eliminate obvious negative choices as soon as possible and narrow the scope of choices; For those who have many ways to solve problems, they should choose the simplest solution.
When solving problems, we should carefully examine the questions, analyze them in depth, deduce them correctly, and beware of omissions; Check carefully after the primary election to ensure accuracy.
Solving methods of multiple-choice mathematics questions in college entrance examination
The following is a list of the top ten problem-solving methods for the multiple-choice math questions in the college entrance examination. These ten methods cover the problem-solving skills of multiple-choice questions in senior high school mathematics. If you can master it skillfully and use it flexibly, it is no problem to get full marks in multiple-choice mathematics.
1. Special value test method
For a general mathematical problem, we can specialize the problem in the process of solving it, and use the principle that the problem does not hold in special circumstances and does not hold in general circumstances to achieve the purpose of removing the false and retaining the true.
Example: the three vertices of △ABC are on the ellipse 4x2+5y2=6, where the two points A and B are symmetrical about the origin O. Let the slope of the straight line AC be k 1 and the slope of the straight line BC be k2, then the value of k 1k2 is
A.-5/4B。 -4/5C.4/5D.2√5/5
Analysis: Because the value of k 1k2 is required, we can know from the stem that the value of k 1k2 is a fixed value. There are no specific positions of A, B and C in the question, because it is a multiple-choice question, so there is no need to solve it. Through simple drawing, we can get the most easily calculated value. We might as well make A and B two vertices on the long axis of the ellipse and C one vertex on the short axis of the ellipse, so we can directly confirm the intersection point and simplify the problem, so we choose B. 。
2. The principle of extremism
Analyze the problem to be studied to the extreme state, so that the causal relationship becomes more obvious, thus achieving the purpose of solving the problem quickly. Extreme value is mainly used to find extreme value, range and analytic geometry. Many problems with complicated calculation steps and large amount of calculation can be solved instantly once extreme value analysis is adopted.
3. Exclusion method
Using the known conditions and the information provided by the selection branch, three wrong answers are eliminated from the four options, so as to achieve the purpose of correct selection. This is a common method, especially when the answer is a fixed value or has a numerical range, special points can be used instead of verification to exclude it.
4. Number-shape combination method
According to the conditions of the topic, make a graph or image that conforms to the meaning of the topic, and get the answer through simple reasoning or calculation with the help of the intuition of the graph or image. The advantage of the combination of numbers and shapes is intuitive, and you can even measure the result directly with a square.
5. Recursive induction
Through the conditional reasoning of the topic, we can find the law and sum up the correct answer.
6. Forward cracking method
Using mathematical theorems, formulas, rules, definitions and meanings, the method of obtaining results through direct calculus and reasoning.
Example: The bank plans to invest part of its funds in Project M and Project N for one year, of which 40% will be invested in Project M, 60% in Project N, and the annual income of Project M will be 65,438+00%, and the annual income of Project N will be 35%. At the end of the year, banks must withdraw funds and pay them to depositors at a certain rebate rate. In order to make the annual profit of the bank not less than 10% and not more than 15% of the total investment of M and N, the minimum rebate rate of depositors is ()
A.5% B. 10%
Analysis: Let * * have funds as α and the depositor's rebate rate χ, and we can get 0.1α≤ 0./kloc-0 /× 0.4α+0.35× 0.6α-χ α≤ 0.15α from the meaning of the question.
The solution is 0. 1≤χ≤0. 15, so choose B.
7. Reverse verification method (dry verification method)
Substitute the selected branch into the stem for verification, so as to deny the wrong selected branch and get the correct method of selecting branch.
Example: Let both sets M and N be positive integer sets N, and map f:M→ map element N in set M to element 2n+n in set N, then the original image of image 37 is () under map f.
a3 b . 4 c . 5d . 6
8. If it is difficult, it is illegal.
When it is difficult to solve the problem from the front, we can find a qualified conclusion step by step from the choice of expenditure, or draw a conclusion from the opposite side.
9. Characteristic analysis method
Analyze the characteristics of topic setting and branch selection, find the law and summarize the correct judgment method.
For example, 256- 1 may be divisible by two numbers between 120 and 130, which are:
A. 123， 125B. 125， 127C
Analysis: The square difference formula of junior middle school is from 256-1= (228+1) (228-1) = (228+1) (21).
10. Appraisal selection method
Some problems cannot (or are not necessary) be accurately calculated and judged due to the limitation of subject conditions. At this time, we can only get the correct judgment method from the surface by means of estimation, observation, analysis, comparison and calculation.
Skills of covering multiple choice questions in mathematics
When doing multiple-choice math questions in the college entrance examination, covering the questions is also a "technical job". You didn't just bring it here to write an answer. So, how to cover the math multiple-choice questions? Here are your techniques for covering multiple-choice questions. Please refer to them.
1. In the multiple-choice math questions in the college entrance examination, we can first exclude two certain wrong options by exclusion, and then choose the right one from the other two options according to our own calculation and understanding of the stem.
2. There is also a special skill in the multiple-choice questions of college entrance examination mathematics. In other words, if you have made three multiple-choice questions in a row, and all of them are the same choice, then you need to check these three multiple-choice questions again, because it is impossible to have the same answer for three multiple-choice questions in a row.
3. In the math multiple-choice questions of the college entrance examination, it can also be verified by data calculation. For the options you are not sure about, you can verify the data in other options after exclusion. If the data has a certain deviation, the option is wrong.
4. There may be some graphic questions in the math multiple-choice questions. If you can't find a solution to this kind of problem, you can use some coordinate knowledge points instead. We don't have to think from the perspective of graphics, but we can think about graphics from other angles and maybe find a suitable way of thinking.
There are some calculation questions in the multiple-choice questions of the college entrance examination, which will require you to get some specific angle data. You can use the relevant data knowledge given in the title, and sometimes you can get some data related to options. For example, if the angle given in the stem is 60 degrees, you can get some 90 degrees or 120 degrees in the options, which is a multiple of 60 degrees.
How to get high marks in math multiple-choice questions;
1. Tips for getting high marks in multiple-choice exams
2. Mathematics multiple-choice questions perfect score skills
3. Ten skills to do multiple-choice questions
4. 12 math problem-solving skills help you get high marks in the college entrance examination.
5. 12 ways to get high marks in mathematics in college entrance examination.
6. Ten Ways to Solve Multiple Choice Questions in Mathematics
7. Eight methods to solve multiple choice questions in mathematics.
8 ... Best problem-solving skills and ideas for big math problems. Senior Tsinghua tells you how to get high marks.
9. How to get a score above 120 in mathematics?
10. Grading skills of mathematics college entrance examination