[2sin50+sin10(1+根号3tan10)]sin80

[2sin50+sin10(1+根号3tan10)]sin80
[2sin50+sin10(1+根号3tan10)]sin80

[2sin50+sin10(1+根号3tan10)]sin80
那是"根号3tan10"还是"根号3"
我就当是根号3了 sin后的2是平方
原式=[2sin(60-10)+sin10+(√3)sin2(10)/cos10]sin(90-10) 用公式sin(A-B)=sinAcosB-cosAsinB
=[(√3)cos10-sin10+sin10+(√3)sin2(10)/cos10 ]cos10
=(√3)cos2(10)+(√3)sin2(10)
=(√3)[cos2(10)+sin2(10)] sin2A+cos2B=1
=√3

[2sin50+sin10(1+根号3tan10)]sin80 (sin80=cos10)
=2sin50cos10+sin10(cos10+√3*sin10)
=2sin50cos10+sin10*2(1/2*cos10+√3/2*sin10)
=2sin50cos10+2sin10sin(10+30)
=2sin50cos10+2sin10cos50 (sin40=cos50)
=2sin(50+10)
=2sin60
=√3