1.本单元重点、难点分析掌握分类计数原理与分步计数原理,并能用它们分析和解决一些简单的应用问题,理解排列、组合的意义,掌握排列数计算公式及组合数计算公式和组合数的性质,并能用它们解决一些简单的应用问题.掌握二项式定理和二项展开式的性质,并能用它们计算和证明一些简 1. The focus of this unit, analysis of difficult to grasp the principle of classification and counting and counting principle, and can use them to analyze and solve some simple application problems, understand the arrangement, the significance of the combination, to understand the arrangement of the number of calculation formulas and combinations of calculation formulas and combinations And can use them to solve some simple application problems.He master the nature of the binomial theorem and the binomial expansion, and can use them to calculate and prove some Jane