“似少条件”类习题解法

• 作 者: 侯娟 李磊
• 机 构: 山东省平邑实验中学!273300,山东省平邑实验中学!273300
• 出 处: 中学物理教学参考
• 发表日期: 2001年07期
• 关键词: 一元二次方程 定值电阻 极值问题 弹性正碰 实数解 数学观念 数学方法 数学运算 方程数 题设

有一类“似少条件”的习题 ,按常规思路求解 ,发现未知量数目多于方程数目 .这类习题常使学生感到困惑 ,认为条件缺少无法求解 .其实这类习题可从如下几方面去寻找解答 .一、运用“比例法”在求解“似少条件”类问题中 ,通过某些方程式的除法运算往往能消去一些未知量 ,使已知

There is a type of “likelihood-less conditions” problem, which is solved by conventional methods and finds that the number of unknowns is more than the number of equations. Such exercises often make students feel puzzled and think that the conditions are lacking and cannot be solved. In fact, such exercises can be searched from the following aspects: Answers: 1. Using the “proportional method” in the “likelihood-less conditions” problem, the division of certain equations can often eliminate some of the unknowns.