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读者诸君,请先看2014年江苏省高考填空题的压轴题:若△ABC的内角满足sinA+2~(1/2)sinB=2sinC,则cosC的最小值是__.本题一反常态,打破了多年的既定模式,不再是以以往的难、繁或偏的面目示人,而显得平易近人:难度不算太大,能力要求也不算太高.从另一方面看,本题题面纯净简约,实则内涵丰富,它以三角形中的正弦定理、余弦定理为载体,考查了利用均值定理求最值等基本知识以及转化思想、方程运用等基本思想,因而大批考生都能作出如下
The readers are gentlemen, please look at the finale of the 2013 college entrance examination fill the title of Jiangsu Province: If the ABC of △ ABC satisfy sinA + 2 ~ (1/2) sinB = 2sinC, the minimum cosC is __. For many years the established model is no longer in the past difficult, complex or partial appearance of people, and it is approachable: the difficulty is not too large, not too high capacity requirements on the other hand, the problem pure and simple , But it is actually rich in content. Based on the sine and cosine theorems in triangles, this paper examines the basic concepts of using the mean value theorem to find out the most significant value, the transformation of ideas, and the application of equations. Thus a large number of candidates can make the following