一、要点分析1.二项式定理的实质是多项式乘法公式(a+b)~2=a~2+ 2ab+b~2,(a+b)~3=a~3+3a~2b+3ab~2+b~3的推广,它揭示了二项式的n次幂的展开式在项数、系数、次数等方面的特点.因此,利用二项式定理求二项展开式中的特定项(如常数项、系数最大的项、有理项等)或某项的系数是二项式定理应用的 First, the point analysis 1. The essence of the binomial theorem is the polynomial multiplication formula (a+b)~2=a~2+ 2ab+b~2, (a+b)~3=a~3+3a~2b+ The generalization of 3ab~2+b~3 reveals the characteristics of binomial n-th expansions in terms of number of terms, coefficients, times, etc. Therefore, the binomial theorem is used to find the specificity of the binomial expansion. Items (such as a constant term, a term with the largest coefficient, a rational item, etc.) or a coefficient of an item are applications of the binomial theorem