cos(π/3 +α) +sin(π/6 +α)
=cos(π/3)cosα-sin(π/3)sinα+sin(π/6)cosα+cos(π/6)sinα
=1/2 cosα-√3/2 sinα+1/2 cosα+√3/2sinα
=cosα这个没有简便方法的吗要不然的话就用和差化积公式cos(π/3 +α) +sin(π/6 +α)=cos(π/2-π/6 +α) +sin(π/6 +α)=sin(π/6 -α)+sin(π/6 +α)=2sin(π/6)cos(-α)=cosα我就是做到这里 =sin(π/6 -α)+sin(π/6 +α)=2sin(π/6)cos(-α)这一步是怎么.. 有点没看懂因为在电脑上打这样公式太麻烦了，就没写，是用和差化各公式sinθ+sinφ = 2 sin[(θ+φ)/2] cos[(θ-φ)/2]2sin(π/6)cos(-α)中的sin(π/6)中的π/6是上一行里的两个角度相加再除以2 cos(-α)中的-α是上一行里的两个角度相减再除以2好的麻烦了谢谢不客气