2. Some questions that judge the correct number of several propositions must be cautious. If you think it is wrong, you'd better find a counterexample and pay attention to the purpose of classification.
3. If there are many situations in the options, consider whether it is suitable for the meaning of the question; You can write more questions about finding the law, or you can deform the original formula to find the law, or you can use special values to test it. Be wary of the options with "or" and "and" in multiple-choice questions to see if you want to choose.
Second, fill in the blanks: 1, attention-the situation of multiple solutions.
2, pay attention to the implicit conditions of the topic, such as quadratic coefficient is not 0, integer in practical problems, etc.
3, pay attention to whether to bring the unit, the expression format-must be the final simplified result.
4. When you really can't find the angle and the length of the line segment, you can try to guess or measure it.
Third, short answer skills: pay attention to standardized answers, and write specifications for the process and conclusion. The calculation questions must be careful, and the final answer should be the simplest to ensure absolute correctness.
1. Simplify the problem before evaluating it. Simplify it first, and pay attention when substituting it for evaluation: the denominator is not zero; Give due consideration to technologies such as total replacement.
2. Solving fractional equations-a compulsory test, also in application problems.
3. To solve the right triangle problem, pay attention to the method of explaining the auxiliary line and the steps of solving the problem. Pay attention to right angles and special angles. When you take an approximate value, you must follow the requirements of the topic.
4. Practical application questions, long questions, read more questions, find the right relationship according to the meaning of the questions, and list equations, inequalities (groups) or functional relationships. Pay attention to the equivalence relation in the topic in order to construct the equation and inequality relation in order to find the value range of the independent variable. After finding the solution of the equation, we should pay attention to the root test, whether it conforms to the actual problem, and remember to choose.
5. Probability problem: list all possible results by drawing a tree diagram, list or enumeration, and then calculate the probability.
6. Scheme design topic: To see the design requirements of the topic clearly, consider the simplest scheme that meets the requirements, not the complicated and beautiful scheme.
Fourth, other answering skills: 1, area problem, the area problem in the senior high school entrance examination is often irregular graphics, which is not easy to solve directly, and often needs the help of area sum and area difference.
2, looking for a regular topic, we should focus on finding the rule, and avoid blindly filling in. If it is a functional relationship, the solution must be tested, including the independent variables. If it is not a functional relationship, we should look for an index or other relationship.
3. Pay attention to the implicit conditions in complex problems, especially in the rectangular coordinate system of circle and plane, and consider using Pythagorean theorem, projective theorem, right triangle solution, area formula, midline on hypotenuse, right triangle inscribed circle radius formula and right triangle circumscribed circle radius formula.
4. In trigonometric function calculation, the angle should be placed in a right triangle, and necessary auxiliary lines can be made. In the application of solving right triangle, we should be familiar with the concepts of elevation angle, depression angle, slope angle and slope.
5. Be familiar with the rules of common auxiliary lines in the circle. Common auxiliary lines in a circle: (1). See the tangent line connecting the center of the circle and the tangent point.
(2) Two circles intersect to connect the male * * * chord and the heart-to-heart line (the heart-to-heart line vertically bisects the male * * * chord).
(3) Two circles are tangent and connected with each other, and the connecting line must pass through the tangent point.
(4) Make the diameter and chord center distance, construct a right triangle, and apply the Pythagorean theorem.
(5) Transform the required angle into a right triangle with circumferential angles with opposite diameters.
(6) To master the side development diagram, sector area and arc length formula of cylinders and cones. When doing the problem of cone, we often grasp two points: First, the length of the cone bus is equal to the fan radius of the side expansion diagram. The second point is that the circumference of the cone base is equal to the arc length of the sector in the side development diagram.