tanx=-2,π⼀2<x<π, 求sin(x+π⼀6) (sin2x+sin^2x)⼀(1-cos2x)

2025-05-09 11:28:36
推荐回答(3个)
回答1:

sin(x+π/6) (sin2x+sin^2x)/(1-cos2x)
=sin(x+π/6)(2sinxcosx+sin^2x)/2sin^2x
=[1/2 +cosx/sinx]sin(x+π/6)
=[1/2+1/tanx]sin(x+π/6)
=0
很高兴为你解决问题

回答2:

0

回答3:

tanx=-2,π/2sinx=2/根号5,cosx=-1/根号5;
sin2x=-4/5;
sin2x+sin^2x=0
sin(x+π/6)(sin2x+sin^2x)/(1-cos2x)=0