函数f(x)=5根号3cos²x 根号3sin²x-4sinxcosx.

(1)f(x)=sinxcosx+√3cos²X-√3/2=sin2x/2+√3cos2x/2+√3/2-√3/2=sin(2x+π/3).(2)f(x)的最小正周期为π,值域是[-1,1]

1,f(x)=sin²x+√3sinxcosx+2cos²x＝1－cos²x＋√3/2sin2x+2cos²x＝cos²x＋√3/2sin2x+1=(

已知:函数f(x)=2sinxcosx+2√3cos²x-√3求:(1)单调增区间和最小正周期；(2)当x∈[-π/4,π/4]时求最值.f(x)=2sinxcosx+2√3cos²

f(x)=2sinxcosx+2√3cos²x-√3=2sinxcosx+√3(2cos²x-1)=sin2x+√3cos2x=2sin(2x+π/3)最小正周期T=2π/2=π,

1f(x)=√3sinπx+cosπx=2（（√3/2）sinπx+（1/2）cosπx）=2sin（πx+π/3）∴最小正周期T=2π/w=2π/π=2值域f（x）∈[-2,2]2-π/2+2kπ＜

1.2sin(30+2a)+4=5sin(30+2a)=1/230+2a=3030+2a=150a=0a=60tana=√32.f(x)=3sin²x+2√3sinxcosx+5cos

我刚答过的题:(I)f(x)=3sin^2x+2√3sinxcosx+5cos^2x=sin^2x+2√3sinxcosx+3cos^2x+2(sin^2x+cos^2x)=sin^2x+2√3sin

解f(x)=√3cos²x+sinxcosx-√3/2=√3*(1+cos2x)/2+(1/2)sin2x-√3/2=(1/2)sin2x+(√3/2)cos2x=sin(2x+π/3)∴T

f(x)=cos^2x-sin^2x+2(根号3)sinxcosx+1=cos2x+(根号3)sin2x+1=2{(1/2)cos2x+[(根号3)/2]sin2x}+1=2sin(2x+派/6)+1

y=sinx^2+根3sinxcosx+2cosx^2=-1/2(1-2sinx^2)+1/2根3*2sinxcosx+2cosx^2-1+3/2=-1/2cos2x+二分之根3倍sin2x+cos2

合一变形

主要用了4个公式cos^2x=(1+cos2x)/2sin^2x=(1-cos2x)/2sin2x=2sinxcosxasinx+bsinx=根号(a^2+b^2)sin(x+arctan(b/a))

f(x)=3sin^2x+2根号3sinxcosx+5cos^2x=3sin^2x+√3sin2x+5cos^2x-4cos^x-4sin^2x+4=2sin(30+2x)+4T=∏最大值为62sin

f(x)=sin2x-2√3(cosx)^2+√3=sin2x-√3(1+cos2x)+√3=sin2x-√3cos2x=2sin(2x-π/3)π/4=再问：π/6=

f(x)=-4*1/2*(1+cos2X)+4√3sinXcosX+5=-2-2cos2X+2√3sin2X+5=2√3sin2X-2cos2X+3=4sin(2X-π/6)+31.当2X-π/6=π

f(x)=sinxcosx+√3(cosx)^2-√3/2=(1/2)sin2x+(√3/2)cos2x=sin2xcosπ/3+cos2xsinπ/3=sin(2x+π/3)1.0

如图

f(x)=sinxcosx+√3(cosx)^2-√3/2=(1/2)sin2x+(√3/2)cos2x=sin2xcosπ/3+cos2xsinπ/3=sin(2x+π/3)

(sqrt是开方)f(x)=5sqrt(3)[cos(2x)]^2+sqrt(3)[sin(2x)]^2-4sin(x)cos(x),由于[cos(2x)]^2+[sin(2x)]^2=1,且2sin

2cos^2-1=cos2xcos^2=(1+cos2x)/2f(x)=sinxcosx-(根号3)cos^2+(根号3)/2=sin2x/2-根号3*(cos2x+1)/2=sin2x/2-根号3*