初二物理教材中,凸透镜成像规律及应用(照相机、幻灯机、放大镜)是同学们学习的一个难点,特别是利用成像规律解答有关习题时,总是分辨不清而解答错误.为了方便识记,同学们可参照教材中的三个图例,在头脑中形成以下图像(形近数学中的数轴),并了解其性质,解题时就会得心应手. In the second physics textbook, the convex lens imaging law and its applications (cameras, slide projectors, and magnifiers) are difficult for students to learn. Especially when using imaging laws to solve the relevant exercises, they are always indistinguishable and cannot be resolved correctly. Students can refer to the three illustrations in the textbook to form the following image (number axis in the form of mathematics) in the mind and understand its nature.