(1)cos^2(C/2)=√3/2*2*sinC/2*cosC/2
cosC/20,有
cosC/2-√3sinC/2=0
sin(PI/6-C/2)=0
C=PI/3
(2)a^2+b^2-2ab*cosC=c^2
(a+b)^2-2ab*(1+cosC)=c*2
有ab=6
S=1/2*ab*sinC=1/2*6*根3/2=3/2*根3
(1)cos^2(C/2)=√3/2*2*sinC/2*cosC/2
cosC/20,有
cosC/2-√3sinC/2=0
sin(PI/6-C/2)=0
C=PI/3
(2)a^2+b^2-2ab*cosC=c^2
(a+b)^2-2ab*(1+cosC)=c*2
有ab=6
S=1/2*ab*sinC=1/2*6*根3/2=3/2*根3