• 已知f(x)=cos(x+2θ)+sin(x-2θ)是奇函数,求θ的值.试题及答案-单选题-云返教育

    • 试题详情

      已知f(x)=cos(x+2θ)+sin(x-2θ)是奇函数,求θ的值.

      试题解答


      见解析
      解:∵f(x)=cos(x+2θ)+sin(x-2θ)是奇函数,
      ∴f(0)=cos(2θ)+sin(-2θ)=0,
      即cos(2θ)-sin(2θ)=0
      ???2
      cos(2θ+
      π
      4
      )=0,
      ∴2θ+
      π
      4
      =
      π
      2
      +kπ,k∈Z,
      解得,θ=
      π
      8
      +
      2
      ,k∈Z.
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