数列0,1,0,-1,0,1,0,-1....的一个通项公式是

A.(-1)^n+1⼀2 B.cos(nπ⼀2) C.cos{(n+1)π⼀2} D.cos{(n+2)π⼀2} 要选哪个答案
2024-12-31 17:45:53
推荐回答(3个)
回答1:

D.cos{(n+2)π/2}

回答2:

(-1){(n+2/2)次方}*(1+(-1){2n+1次方})/2

回答3:

n,n+1,n.n-1,n,n+1,n,n-1