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怎样阅读数学教科书?…满纸是枯燥无味的说明,是一些毫无感情的符号,看不多时就使人感到疲倦。《数学》果真是如此枯燥乏味吗?不!问题是怎样读?如果你——譬如说,现在你正在翻阅着数学教本第一册三角部分的第143页例4。把一边半径为R的圆木,锯成横截面为矩形的木料,怎样锯法才能使横截面的面积最大? 解一 (略解,以下解法均为略解)设矩形对角线与一边的夹角为θ,则
How to read math textbooks?... Full paper is a boring explanation. It is a symbol of emotionlessness. When it is too late, it makes people feel tired. Was mathematics so boring? No! The question is how to read it. If you—for example, you are now reading Example 4 on page 143 of the first part of the mathematics textbook. How can the sawing method maximize the cross-sectional area of a log with a radius of R? A solution (slightly solution, the following solution is a slight solution) Set the angle between the diagonal of the rectangle and the side For θ, then