• 操作变换记为P1(x,y),其规则为:P1(x,y)=(x+y,x-y),且规定:Pn(x,y)=P1(Pn-1(x,y)),n是大于1的整数,如:P1(1,2)=(3,-1),P2(1,2)=P1(P1(1,2))=P1(3,-1)=(2,4),???P2012(1,-1)= .试题及答案-填空题-云返教育

    • 试题详情

      操作变换记为P1(x,y),其规则为:P1(x,y)=(x+y,x-y),且规定:Pn(x,y)=P1(Pn-1(x,y)),n是大于1的整数,如:P1(1,2)=(3,-1),P2(1,2)=P1(P1(1,2))=P1(3,-1)=(2,4),???P2012(1,-1)=         

      试题解答


      (21006,-21006
      解:∵P1(x,y)=(x+y,x-y),且规定:Pn(x,y)=P1(Pn-1(x,y)),
      P
      1(1,-1)=(0,2 ),P2(1,-1)=P1(P1(1,-1))=P1(0,2)=(2,-2),
      P
      3(1,-1)=P1(P2(1,-1))=P1(2,-2)=(0,4),
      P
      4(1,-1)=P1(P3(1,-1))=P1(0,4)=(4,-4),…
      可见,当n为奇数时,P
      n (1,-1)=(0,-2
      n+1
      2
      ),当n为偶数时,Pn (1,-1)=(2
      n
      2
      ,-2
      n
      2
      ),
      ∴P
      2012(1,-1)=(21006,-21006),
      故答案为 (2
      1006,-21006).
    MBTS ©2010-2016 edu.why8.cn