• 已知定义域为R的函数f(x)满足;f(x+y)=f(x)f(y),且f(3)>1.(1)求f(0);(2)求证:f(-4)<1.试题及答案-单选题-云返教育

    • 试题详情

      已知定义域为R的函数f(x)满足;f(x+y)=f(x)f(y),且f(3)>1.
      (1)求f(0);
      (2)求证:f(-4)<1.

      试题解答


      见解析
      解:(1)令x=0,y=3得
      f(3)=f(0)f(3)
      ∵f(3)>1
      ∴f(0)=1
      (2)证明:∵f(x+y)=f(x)f(y),
      ∴f(3)=[f(1)]
      3>1
      ∴f(1)>1
      ∴f(4)=[f(1)]
      4>1
      ∵f(4-4)=f(4)f(-4)
      即f(-4)=
      1
      f(4)
      <1
    MBTS ©2010-2016 edu.why8.cn