f(x)=sinx^2+根号3*sinx*cosx+2cos^2 x属于R 该怎样化简?
问题描述:
f(x)=sinx^2+根号3*sinx*cosx+2cos^2 x属于R 该怎样化简?
答
答:利用公式:(sinx)^2+(cosx)^2=1cos2x=2(cosx)^2-1=1-2(sinx)^2sin2x=2sinxcosxsin(a+b)=sinacosb+cosasinbf(x)=(sinx)^2+√3sinxcosx+2(cosx)^2=1+(cosx)^2+(√3/2)*2sinxcosx=(1/2)*(cos2x+1)+(√3/2)sin2x+1=(...