可能是考虑到教学进度的原因 ,在国内的中学生数学竞赛中 ,与二项式有关的试题比较少 ,但也时有出现 .还有些竞赛题虽不明显属于二项式的范围 ,但运用二项式定理可以巧妙地加以解决 .对于二项式定理 ,应熟练掌握以下三个方面的内容 :1) (a +b) n(n∈N )的展开式的通项公式为Tr+ It may be due to the reason of teaching progress. In the domestic mathematics competition for middle school students, the questions related to the binomial formula are relatively few, but they also appear from time to time. Although some contest titles are not obviously in the scope of the binomial formula, they are used two times. The term theorem can be skillfully solved. For binomial theorem, we should be proficient in the following three aspects: 1) (a + b) n(N ∈ N) expansion of the general formula is Tr +