《数学爱好者》杂志社从本期开始推出“名师互动”活动,活动内容是每期将有一道各地著名教师出的难题。题刊登在本栏目中,老师和学生解出此题后将正确答案寄给杂志社,同时再附一道新的题,我们将从答案正确的稿件中选一个新颖的题刊登在下一期的名师互动栏目中。我们将会从参与活动的老师和学生中评出优秀者,并赠送精美礼品。本期题目为: “Mathematics Lovers” magazine launched the “Master Teacher Interaction” activity from this issue. The content of the activity is that each period will have a difficult problem for famous teachers from all over the country. The questions are published in this column. Teachers and students solve the problem and send the correct answer to the magazine. At the same time, a new question is attached. We will select a novel question from the correct answer and publish it in the next session. In the column. We will judge outstanding people from teachers and students participating in the event and present wonderful gifts. The title of this issue is: