化简求值:a(x-a)^2n-(a-x)^2n,n是正整数,x=1,a=2
问题描述:
化简求值:a(x-a)^2n-(a-x)^2n,n是正整数,x=1,a=2
答
a(x-a)^2n-(a-x)^2n=2(1-2)^2n-(2-1)^2n=2(-1)^2n-(1)^2n
因为n是正整数,则2n为正偶数,
(-1)^2n=1
所以原式=2(-1)^2n-(1)^2n=2×1-1=1a(x-a)^2n-(a-x)^2n+1a(x-a)^2n-(a-x)^(2n+1)=2(-1)^2n-(1)^(2n+1)因为n是正整数,则2n为正偶数,2n+1为正奇数(-1)^2n=1 (1)^(2n+1)=1所以原式=2(-1)^2n-(1)^(2n+1)=2×1-1=1