1.若SIN(α+β)除以SIN(α-β)等于p除以q,则tanα除以tanβ等于?2.sin(45°—3X)cos(60°—3X)—cos(30°+3X)sin(45°+3X)

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1.若SIN(α+β)除以SIN(α-β)等于p除以q,则tanα除以tanβ等于?2.sin(45°—3X)cos(60°—3X)—cos(30°+3X)sin(45°+3X)
1.若SIN(α+β)除以SIN(α-β)等于p除以q,则tanα除以tanβ等于?
2.sin(45°—3X)cos(60°—3X)—cos(30°+3X)sin(45°+3X)

1.若SIN(α+β)除以SIN(α-β)等于p除以q,则tanα除以tanβ等于?2.sin(45°—3X)cos(60°—3X)—cos(30°+3X)sin(45°+3X)
1.因为SIN(α+β)=(SINα*cosβ+cosα*sinβ)/(SINα*cosβ-cosα*sinβ)=p/q
设x=tanα/tanβ=SINα*cosβ/cosα*sinβ
x+1=SINα*cosβ+cosα*sinβ/cosα*sinβ
x-1=SINα*cosβ-cosα*sinβ/cosα*sinβ
x+1/x-1=p/q
x=tanα/tanβ=p+q/p-q
2.sin(45°—3X)=cos(45°+3X)
cos(30°+3X)=sin(60°—3X)
所以 原式=cos(45°+3X)cos(60°—3X)-sin(45°+3X)sin(60°—3X)
=cos(45°+60°)=cos45°*cos60°-sin45°*sin60°