2. Special value method: (Special value elimination method) Some multiple-choice questions involve mathematical propositions related to the letter range;
When solving this kind of multiple-choice questions, we can consider selecting some special values from the range of values, substituting them into the original proposition for verification, and then eliminating the wrong ones and keeping the correct ones.
3. Exclusion method: Return the four conclusions given in the topic to the original topic one by one for verification, and eliminate the mistakes until the correct answer is found.
4. Phase-out method: If we do not do it in one step, but in one step, then we will adopt the strategy of "take a walk and have a look";
Each step is compared with four conclusions, and it is impossible to eliminate them, so it is possible that all three wrong conclusions will be eliminated before the last step.
5. Number-shape combination method: according to the internal relationship between the conditions and conclusions of mathematical problems, it not only analyzes its algebraic significance, but also reveals its geometric significance;
Make the relationship between quantity and figure skillfully and harmoniously combined, and make full use of this combination to seek ideas and solve problems.