• cos67.5°cos22.5°+sin22.5°sin67.5°等于试题及答案-单选题-云返教育

    • 试题详情

      cos67.5°cos22.5°+sin22.5°sin67.5°等于         

      试题解答


      C
      cos67.5°cos22.5°+sin22.5°sin67.5°=cos(67.5°-22.5°)=cos45°=
      故选C.
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