问题 填空题

a4(x+1)4+a3(x+1)3+a2(x+1)2+a1(x+1)+a0=x4,则a3-a2+a1=______.

答案

[(x+1)-1]4=C40(x+1)4-C41(x+1)3+C42(x+1)2-C43(x+1)+C44

又由题意,[(x+1)-1]4=a4(x+1)4+a3(x+1)3+a2(x+1)2+a1(x+1)+a0

则a3=-C41,a2=C42,a1=-C43

有a3-a2+a1=(-C41)-C42+(-C43)=-14.

答案:-14

判断题
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