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贵刊83年第三期上刊载了《谈谈平面几何中最大(小)值问题》一文,阅后获益非浅。结合本人的教学实践,作为对上文的补充,笔者也来谈谈平面几何中的最值问题。在初中数学总复习中,教者讲练了如下一道题。例1.半径为1的半圆内接等腰梯形,其下底是半圆直径。(1)试求它的周长 y 与腰长 x 之间的函数关系式,并写出定义域;(2)当腰长多少时周长有最大值?(本例和八二年天津市初中升学试题类似)
In your third issue of the 83rd issue, you published the article “Talking about the Maximum (Small) Value Problem in Plane Geometry”. In combination with my teaching practice, as a supplement to the above, the author also came to talk about the most value problem in plane geometry. In the review of junior high school mathematics, the teacher practiced the following question. Example 1. A semicircle with a radius of 1 is inscribed in an isosceles trapezoid and its bottom is a semicircle diameter. (1) Try to find the functional relationship between its perimeter y and the waist length x, and write out the definition domain; (2) What is the maximum circumference when the waist length? (This case and the Tianjin city in 1982 The junior high school entrance examination questions are similar)