sin2xsin3x化简过程

贲汤苑4394用初等数学(不用导数法)方法求y=sin x+sin 2x+sin 3x的最值. -
姚琬具18915854545 ______ 麻烦哦~要先化简,sin3x难化啊~ 把它化成:sina(2x+x) =sina2xcosx+cos2xsinax=2sinaxcosxcosx+(cosxcosx-sinxsinx).sinx=....

贲汤苑4394sin4xsin2x - sinxsin3x=sinxsin5x 求化简过程 -
姚琬具18915854545 ______ sin4xsin2x=-1/2[cos(4x+2x)/2-cos(4x-2x)/2]=-1/2(cos3x-cosx) sinxsin3x=-1/2[cos(x+3x)/2-cos(x-3x)/2]=-1/2(cos2x-cosx) sin4xsin2x-sinxsin3x=[-1/2(cos3x-cosx)]-[-1/2(cos2x-cosx)]=1/2(cos2x-cos3x)=1/2*[(-2)sin(2x+3x)sin(2x-3x)]=-sin5xsin(-x)=sinxsin5x

贲汤苑4394求化简 sinX+sin2X+sin3X -
姚琬具18915854545 ______ sin2x=2sinxcosxsin3x=sin(2x+x)=sin2xcosx+cos2xsinx=(2sinxcosx)cosx+(1-2sinxsinx)sinxsinX+sin2X+sin3X=sinx+2sinxcosx+(2sinxcosx)cosx+(1-2sinxsinx)sinx=2sinxcosx+(2sinxcosx)cosx-2sinxsinxsinx=sinxcosx+2sinxsin2x

贲汤苑4394sin(2x)=2sin(x)cos(x),那么sin(3x)怎么表示呢,sin(Nx)呢 -
姚琬具18915854545 ______[答案] sin(3x)=sin(2x+x)=sin2xcosx+cos2xsinx=2sinx(cosx)^2+sinx(cosx)^2-(sinx)^3=3sinx(cosx)^2-(sinx)^3 sin(Nx)一次类推

贲汤苑4394满足等式cos2xcos3x=sin2xsin3x的角是 -
姚琬具18915854545 ______ 原式即化为cos2xcos3x-sin2xsin3x=0 cos(2x+3x)=0 所以5x=kπ+π/2 其实这道题稍稍思考就行咯,你应该有学过公式:cos(a+b)=cosacosb-sinasinb cos(a-b)=cosacosb+sinasinb

贲汤苑4394sin2xsin3x=cos2xcos3x,则x的值可能为 -
姚琬具18915854545 ______[选项] A. ∏/10 B. ∏/6 C. ∏/5 D. ∏/4 要理由

贲汤苑4394sin(2x)=2sin(x)cos(x),那么sin(3x)怎么表示呢,sin(Nx)呢 -
姚琬具18915854545 ______ sin(3x)=sin(2x+x)=sin2xcosx+cos2xsinx=2sinx(cosx)^2+sinx(cosx)^2-(sinx)^3=3sinx(cosx)^2-(sinx)^3 sin(Nx)一次类推

贲汤苑4394满足等式cos2xcos3x=sin2xsin3x的角是 -
姚琬具18915854545 ______[答案] 原式即化为cos2xcos3x-sin2xsin3x=0 cos(2x+3x)=0 所以5x=kπ+π/2 其实这道题稍稍思考就行咯,你应该有学过公式:cos(a+b)=cosacosb-sinasinb cos(a-b)=cosacosb+sinasinb

贲汤苑43942sin2X - sin(2X+π/3)化简怎么化啊 -
姚琬具18915854545 ______[答案] 原式=2sin2x-(sin2xcosπ/3+cos2xsinπ/3) =2sin2x-1/2*sin2x-√3/2*cos2x =3/2*sin2x-√3/2*cos2x =√3(√3/2sin2x-1/2cos2x) =√3(sin2xcos30°-cos2xsin30°) =√3sin(2x-π/6)