化简f(x)=cosx+cos(x+派/3).RT

化简f(x)=cosx+cos(x+派/3).RT
化简f(x)=cosx+cos(x+派/3).
RT

化简f(x)=cosx+cos(x+派/3).RT
f(x)=cosx+cosxcosπ/3-sinxsinπ/3
=cosx+cosx*1/2-sinx*√3/2
=cosx*3/2-sinx*√3/2
=√3(cosx*√3/2-sinx*1/2)
=√3(cosxcosπ/6-sinxsinπ/6)
=√3cos(x+π/6)

y=cos(x+π/3)+cosx
=cosxcosπ/3-sinxsinπ/3+cosx
=cosx/2-√3sinx/2+cosx
=3cosx/2-√3sinx/2
=√3(√3/2*cosx-1/2*sinx)
=√3(sinπ/3cosx-cosπ/3*sinx)
=√3sin(π/3-x)