极限法就是把自变量无限趋近于某个数值时,使因变量也无限趋近于某个值.极限法是科学研究的重要方法.在初中阶段将这种方法渗透到教学中,有利于发展学生的科学思维能力.教材从第一章第一节就开始渗透极限法,在探究声音的传播是否需要介质时, The limit method is to infinitely approach the independent variable to a certain value, so that the dependent variable is also infinitely close to a certain value. The limit method is an important method of scientific research. In the junior middle school, this method is infiltrated into the teaching and is beneficial to Develop students’ scientific thinking skills. Textbooks begin to penetrate the limit method from the first section of the first chapter. When it comes to exploring whether sound transmission requires media,