已知函数f（x)=((根号3)/2)*sin2x-cos²x-1/2,x属于R

f（x)=√3/2*sin2x-cos²x-1/2
=√3/2*sin2x-(2cos²x-1)/2-1
=√3/2*sin2x-cos2x/2-1
=sin2x*cosπ/6-cos2xsinπ/6-1
=sin(2x-π/6)-1
f（C）=0
f（C）=sin(2C-π/6)-1=0
sin(2C-π/6)=1
2C-π/6=π/2
2C=2π/3
C=π/3
向量m=（1,sinA）,与向量n=(2,sinB)共线
1*sinB=2sinA
sinB=2sinA
b=2a
cosC=(a^2+b^2-c^2)/2ab
1/2=(5a^2-3)/4a^2
4a^2=10a^2-6
6a^2-6
a^2=1
a=1或a=-1(舍去)
b=2a=2*1=2