解关于x的不等式 x2-x-a(a-1)>0

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解关于x的不等式 x2-x-a(a-1)>0
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解关于x的不等式 x2-x-a(a-1)>0
解关于x的不等式 x2-x-a(a-1)>0

解关于x的不等式 x2-x-a(a-1)>0
(x-a)(x+a-1)>0
所以零点是a和-a+1
比较两个大小
a>-a+1
则a>1/2
a<-a+1,则a<1/2
a=1/2,则(x-1/2)²>0,x-1/2≠0
所以
a<1/2,x-a+1
a=1/2,x≠1/2
a>1/2,x<-a+1,x>a

[sin(x+π/12)+sin(x-π/12)][sin(x+π/12)-sin(x-π/12)]=1/4
(sinxcosπ/12+cosxsinπ/12+sinxcosπ/12-cosxsinπ/12)(sinxcosπ/12+cosxsinπ/12-sinxcosπ/12+cosxsinπ/12)=1/4
4sinxcosπ/12*cosxsinπ/12=1/4
(...

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[sin(x+π/12)+sin(x-π/12)][sin(x+π/12)-sin(x-π/12)]=1/4
(sinxcosπ/12+cosxsinπ/12+sinxcosπ/12-cosxsinπ/12)(sinxcosπ/12+cosxsinπ/12-sinxcosπ/12+cosxsinπ/12)=1/4
4sinxcosπ/12*cosxsinπ/12=1/4
(2sinxcosx)(2sinπ/12cosπ/12=1/4
sin2xsinπ/6=1/4
sin2x=1/2
π/4π/2<2x<π
所以2x=5π/6
x=5π/12=π/4+π/6
所以tanx=(tanπ/4+tanπ/6)/(1-tanπ/4tanπ/6)=2+√3

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