若f(x)定义域为R,则有mx^2+(2m-1)x+1≠0,(2m-1)^2-4m<0,4m^2-8m+1<0,m^2-2m+1/4<0,
(m-1)^2<3/4,-√3/2<m-1<√3/2,1-√3/2<m<1+√3/2
所以,m∈(1-√3/2,1+√3/2)
若f(x)定义域为R,则有mx^2+(2m-1)x+1≠0,(2m-1)^2-4m<0,4m^2-8m+1<0,m^2-2m+1/4<0,
(m-1)^2<3/4,-√3/2<m-1<√3/2,1-√3/2<m<1+√3/2
所以,m∈(1-√3/2,1+√3/2)