1,-3,5,-7,9,-11,13.第N个数是多少?
问题描述:
1,-3,5,-7,9,-11,13.第N个数是多少?
找规律的,请多多指教...
答
(2n-1)×(-1)^(n+1)
1,-3,5,-7,9,-11,13.第N个数是多少?
找规律的,请多多指教...
(2n-1)×(-1)^(n+1)