sinx+cos(x+π/3)化简为什么sinx+cosxcos(π/3)-sinxsin(π/3) =sin(x-π/3)

sinx+cos(x+π/3)化简为什么sinx+cosxcos(π/3)-sinxsin(π/3) =sin(x-π/3)
sinx+cos(x+π/3)化简
为什么sinx+cosxcos(π/3)-sinxsin(π/3)
=sin(x-π/3)

sinx+cos(x+π/3)化简为什么sinx+cosxcos(π/3)-sinxsin(π/3) =sin(x-π/3)
童鞋,你写的sinx+cosxcos(π/3)-sinxsin(π/3)=sin(x-π/3)是不对的!

如果把x=0带入,左边和右边根本不等啊!


不做三角函数很多年,做的不一定对啊：

如果你学了和差化积,那就直接用和差化积：