在解题中,视具体情况恰当选择参数,使之能清楚地表示各量间的联系和变化,又便于计算,这是发挥参数“活力”的关键。本文拟从如下几方面举例说明。一、参数几何意义的应用这方面文献颇多,本文从略。二、参数在求解极值问题中的应用 In the problem-solving problem, the parameters are appropriately selected according to the specific circumstances so that they can clearly express the linkages and changes between the quantities and are easy to calculate. This is the key to the “vigor” of the parameters. This article is intended to illustrate from the following aspects. First, the application of the parameters of geometric significance This literature is quite numerous, this article is abbreviated. Second, the application of parameters in solving extreme problems