在中学数学解题中有许多常见错误不是因为审题不清,也不是因为方法不当,而根本原因却在于解题过程中因忽略了某些参变元(量)范围的限制而产生的。事实上,某些参变元的范围在问题中起着十分关键的作用,因此,要想提高解题的正确率,就必须重视在解 There are many common mistakes in solving problems in middle school mathematics, not because the questions are unclear, or because of improper methods, but the root cause is that in the process of solving problems, it is caused by ignoring the limitation of certain parameters (quantifiers). In fact, the scope of some of the participating variables plays a crucial role in the problem. Therefore, if we want to improve the accuracy of the problem, we must pay attention to the solution.