设fx 2根号3sin x(π-x)sinx-(sinx-cosx)^2
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1|a|^2=4sinx^2,|b|^2=1|a|=|b|,即:4sinx^2=1即:sinx^2=1/4,x∈[0,π/2]即:sinx=1/2,故:x=π/62f(x)=a·b=(√3sinx,s
17/4根号3/2-321/64a/2带入后,平方,化简
f(x)=a^2+2aba^2=1,a*b=(sinx)^2+√3sinx*cosx=1/2-1/2cos2x+√3/2sin(2x)=1/2+sin(2x-π/6)所以f(x)=1+2(1/2+si
f(x)=1/2sinx+根号3/2cosx=sin(x+π/6)f(A)=sin(A+π/6)=3/2不可能
f(x)=1/2sinx+根号3/2cosx=sin(x+π/3)所以最小正周期T=2π/1=2π因-1≤sin(x+π/3)≤1值域为[-1,1]
第一题:(1):f(x)=2倍sinx的平方+2倍根号3cosxsinx-1化简为:f(x)=-2cos(2x+π/3)显然f(x)在x=0处去最小为-1;在x=π/3处取最大为2(2):f(x)=-
f(x)=2cosx*sin(x+π/3)-√3sinx^2+sinx*cosx=2cosx*(sinxcosπ/3+cosxsinπ/3))-√3sinx^2+sinx*cosx=sinxcosx+
根号下(sinx-(sinx)^3)dx=根号下(sinx[1-(sinx)^2])dx=根号下(sinx*cos^2x)dx=根号下(sinx)*cosxdx=根号下(sinx)*dsinx=2/3
f(x)=(sinx)^2-√3sinxcosx=(1-cos2x)/2-√3/2sin2x=-(√3/2sin2x+1/2cos2x)+1=-sin(2x+π/6)+1(1)当0≤x≤3π/2时,π
1)由三角函数和差化积公式:f(x)=2sin(x+x+π/3)/2cos(x-x-π/3)/2=2sin(x+π/6)cos(π/6)=√3sin(x+π/6)f(x)的最小值为-√3.当x+π/6
f(x)=a(a+2b)=1+2(sin²x+√3sinxcosx)=1+(1-cos2x)+√3sin2x=2+√3sin2x-cos2x=2+2sin(2x+π/6)∴由2kπ-π/2≤
1、f(x)=2sin²x+2√3sinxcosx=1-cos2x+√3sin2x=2sin(2x-π/6)+1.当x∈[0,π/2]时,f(x)∈[2,3];若f(x)关于直线x=a对称,
nnd离心率是啥?我得补补了.
设x=sinxf(-x)+3f(x)=4*x*√(1-x^2).①设x--sinxf(x)+3f(-x)=4*(-x)*√(1-x^2).②①②分别相加相减得到③④4f(x)+4f(-x)=0.③2f
最佳方法:sinx>根号3*cosxsinx-根号3*cosx>02*sin(x-π/3)>0(辅助角公式)sin(x-π/3)>0"正弦上为正"则x-π/3在X轴上方即2kπ
m-n=(cosx-1,sinx-根号3)|m-n|^2=5即(cosx-1)^2+(sinx-根号3)^2=5cos^2x-2cosx+1+sin^2x-2根号3sinx+3=52cosx+2根号3
=-sinx/(1-cosx)*√[(1/cosx-1)/(1/cosx+1)]]=-sinx/(1-cosx)*[(1-cosx)/|sinx|]sinx>0=-1sinx再问:化简,不用求值再答:
f(x)=2×(1/2sinx-√3/2cosx)=2×(cosπ/3sinx-sinπ/3cosx)=2sin(x-π/3)x∈【-π,0】x-π/3∈【-4π/3,-π/3】x-π/3∈【-π/2