已知函数f(x)=根号3sinxcosx-1/2cos2x-1 1.求函数f(x)的最小值
问题描述：
已知函数f(x)=根号3sinxcosx-1/2cos2x-1 1.求函数f(x)的最小值
2.设△ABC的内角A,B,C所对的边分别是a,b,c,且c=根号7,f(C)=0,sinB=3sinA求△ABC面积
答
f(x)=√3sinxcosx-1/2cos2x-1=(√3/2)sin2x-(1/2)cos2x-1=cosπ/6sin2x-sinπ/6cos2x-1=sin(2x-π/6)-11.-1≤sin(2x-π/6)≤1f(x)min=-1-1=-22.f(C)=sin(2C-π/6)-1=02C-π/6=π/2C=π/3在△ABC中b/sinB=a/sinAb=asi...