已知f(x)=cosx(2根3sinx-cosx)
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F(x)=m.n=2根号3sinxcosx+cos^2x-sin^2x=根号3sin2x+cos2x=2sin(2x+π/6)
f(x)=sinxcosx+cos²x-1/2=1/2*sin2x+1/2*(1+cos2x)-1/2=1/2*sin2x+1/2*cos2x=√2/2*(√2/2*sin2x+√2/2*c
1.f(x)=2cosx*sin(x+π/3)-√3sin^2x+sinx*cosx=2cosx*sin(x+π/3)-2sinx*[(√3/2)sinx-(1/2)cosx]=2cosx*sin(x
f(x)=2cosx(cosx+根号3sinx)=2cos^2x+2*根号3sinx*cosx=cos2x+根号3sin2x+1当cos2x=1/2sin2x=根号3/2有最大值3当cos2x=-1/
f(x)=sin2x-2cosx^2-1=sin2x-cos2x-2=根号2sin(2x-45)-2最小正周期为派最大值为根号2-2将所有点纵坐标变为2倍,向左平移四分之派个单位,将所有点的横坐标变为
1.f(x)=1/2(1-cos2x)+sin2x+3/2(1+cos2x)=cos2x+sin2x+2=2^(1/2)sin(2x+3.14/4)+2,所以最大值为2^(1/2)+2,x的值为-(3
再问:最后的f(x)=2-2x^2没看懂再答:令cos(x/2)=t,式子就变成:f(t)=2-2t²所以,f(x)=2-2x²再问:好的,谢谢
ac=b^2=a^2+c^2-2accosx==>ac(1+2cosx)=a^2+c^2≥2ac==>cosx≥1/2==>0<x≤π/3f(x)=sinx/3cosx/3+√3(cosx/3)^2=
1.f(x)=1/2cos2x+√3/2sin2x+cos^2x-sin^2x=3/2cos2x+√3/2sin2x=√3sin(2x+π/3)2.x属于【-π/12,π/2】,所以2x+π/3属于【
f(x)=5√3sinxcosx+2cos^2x+sin^2x+4cos^2x+3/2=5√3/2sin2x+6cos^2+sin^2x+3/2=5√3/2sin2x+6cos^2x-3+3+sin^
(1)f(x)=.2sinx3(sinx−cosx)sinx+cosxcosx.=sin2x+3cos2x=2sin(2x+π3)…(3分)所以函数f(x)的最小正周期为π…(3分)(2)
这类题全都是要把表达式用倍角公式等化简成y=Asin(ωx+φ)形式.f(x)=2cosxsinx-2cosxcosx+1=sin2x-cos2x=√2*sin(2x-π/4)T=π,最大值√2,最小
提示:sin45°等于cos45°【很重要】如sin2x-cos2x就可以写成sin2x*cos45°-sin45°cos2x;F(X)=sinX*sinX-sinxcosx(sin2x=2sinxc
f(x)=m*n=2√3sinxcosx+(cosx-sinx)(cosx+sinx)=√3sin2x+cos2x=2sin(2x+π/6),所以,函数最小正周期为2π/2=π,值域为[-2,2].再
这个简单:f(x)=2cosx(sinxcos(pi/3)+cosxsin(pi/3))-根号33sin^2x+sinx*cosx=2sinxcosx+根号3cos2x=2sin(x+pi/3)所以:
f(x)=2cosx(sinx-cosx)+2=2cosx*sinx-2(cosx)^2+2=sin2x-[2(cosx)^2-1]+1=sin2x-cos2x+1=根号(2)*sin(2x-π/4)
1、f(x)=(√3/2)sin2x+(1/2)cos2x=sin(2x+π/6)周期T=2π/2=π当x∈【0,π/2】时,2x+π/6∈【π/6,7π/6】则sin(2x+π/6)∈【-1/2,1
f(x)=1/2sin(2x/3)+√3(1+cos(2x/3))/2=1/2sin(2x/3)+√3/2cos(2x/3)+√3/2=sin(2x/3+π/3)+√3/2