现代教学观要求教师用发展的观点看待学生 ,着眼于调动学生学习的积极性和主动性 ,教给学生学习的方法 ,培养学生的学习能力 .在实际教学活动中 ,教师要为学生创设问题情境 ,提供适当的问题 ,引起他们的思维 ,启发他们的思考 .本文举例谈谈如何创设问题情境 .例 1　已知实数a , The modern teaching concept requires teachers to look at students from the point of view of development, focus on mobilizing the enthusiasm and initiative of student learning, teach students how to learn, and develop students’ learning ability. In actual teaching activities, teachers should create problem situations for students. To provide appropriate questions that arouse their thinking and inspire their thinking. This article gives an example of how to create problem situations. Example 1 Known real numbers a,