数学公式是数学知识的精髓,一个数学公式往往就揭示了一类问题的普遍规律,是解决这类问题的通用方法.数学公式的内涵深刻,是很多数学家经过长期而艰苦的观察、实验、论证而得出的.然而,不少老师对数学公式的课堂教学还过于简单化,学生对公式发现的体验过程还不够,因而理解不够深刻,记忆不长久,机械套用公式的现象还很严重.一个发人深省的例子就是2011年高考数学陕西卷第18题:叙述并证明余弦定理.很多考生不适 Mathematical formula is the essence of mathematical knowledge, a mathematical formula often reveals a general law of a class of problems, is a common method to solve such problems.Mathematical formula profound connotation, many mathematicians through long-term and painstaking observation, experiment, However, many teachers on the mathematics formula classroom teaching is too simplistic, students experience the process of formula discovery is not enough, so understanding is not deep enough, memory is not long, the phenomenon of mechanical formula is still very serious. A thought-provoking example is the 2011 college entrance examination mathematics Shaanxi Volume 18: describe and prove the cosine theorem. Many candidates are not suitable