Question

(1)項(xiàng)數(shù):二項(xiàng)式共有________項(xiàng).?

(2)二項(xiàng)式系數(shù):二項(xiàng)式展開式第r+1項(xiàng)的二項(xiàng)式系數(shù)為_________(r=0,1,2,…,n).?

(3)通項(xiàng)公式:(a+b)ⁿ的二項(xiàng)展開式中的_______叫做二項(xiàng)式展開式的通項(xiàng),用________表示,則有_________.?

(4)指數(shù)特征:二項(xiàng)式展開式中a的指數(shù)由n_______0,b的指數(shù)由0_________,各項(xiàng)a、b的指數(shù)之和都等于__________,其中a、b可以為數(shù),也可以是式.

Answer 1

(1)n+1項(xiàng)　

(2)　

(3)第r+1項(xiàng)    T_r+1     T_r+1=a^n-rb^r?

(4)逐漸遞減1　逐漸遞增1　n