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历年的高考试题中都有一部分是将课本例题、习题进行“改头换面、重新包装”编制而成的,也因此,对课本中一些结论的合理记忆,会帮助我们提高解题速度.下面以2013年、2014年高考试题为例,剖析一个课本习题结论在高考解题中的妙用.结论展示在△ABC中,若内角A,B,C的对边分别为a,b,c则a=bcos C+ccos B,b=ccos A+acos C,c=acos B+bcos A;该结论用余弦定理不难证得,它揭示了三角形两边及其对角的余弦与第三边的关系,适用于解决相关的解三角形问题.下面展示该结论在高考中的几种应用.
Over the years the college entrance examination questions are part of the textbook examples, exercises for “make a difference, repackage ” compiled from, and therefore, some reasonable conclusions in the textbook memory, will help us to improve the speed of problem solving. 2013, 2014 college entrance examination test as an example, analyze a textbook exercises conclusion in the college entrance examination problem solving magical effect.Conclusion In the △ ABC, if the inner corner of the A, B, C opposite sides were a, b, c, then a = This conclusion is not difficult to prove with the cosine theorem, which reveals the relationship between the cosines of the two sides of the triangle and its diagonal, and the third side, Suitable for solving the problem of solving the triangle.The following shows the conclusion of several applications in the college entrance examination.