题目内容
f(k+1)=f(k)+k.
A.f(k+1)=f(k)+k+1
B.f(k+1)=f(k)+k-1
C.f(k+1)=f(k)+k
D.f(k+1)=f(k)+k+2
A.f(k+1)=f(k)+k+1 B.f(k+1)=f(k)+k-1
C.f(k+1)=f(k)+k D.f(k+1)=f(k)+k+2