3解:(1)由V3sinA-cosA=2得,2sinA-2cosA=l,即sin(A-石)=l22π3(2)由题设条件和正弦定理2bsin C=csin 2B2 sin Bsin C=2sin C sin B cos B0,)sin Bsin C0,进而cosB2,海到于是C=π-A-B=12