(a-b)的2n次方-2(b-a)的2n-1次方-2/3(b-a)的2n次方-1/2(a-b)的2n-1次方
=(a-b)的2n次方+2(a-b)的2n-1次方-2/3(a-b)的2n次方-1/2(a-b)的2n-1次方
=1/3(a-b)的2n次方+3/2(a-b)的2n-1次方
=1/3-3/2
=-7/6
说明:2n是偶数 2n-1是奇数
∴(a-b)的2n次方=(b-a)的2n次方
(b-a)的2n-1次方=-(a-b)的2n-1次方
(-1)的2n次方=1
(-1)的2n-1次方=-1