函数f(x)=mx/4x-3(x不等于3/4)在定义域内恒有f{f(x)}=x 则m=

函数f(x)=mx/4x-3(x不等于3/4)在定义域内恒有f{f(x)}=x 则m=f{f(x)}=x f{f(x)}=f[mx/(4x-3)]=m*[mx/(4x-3)]/{4[mx/(4x-3)]-3}=m²x/(4mx-12x+9)=x可得 m²+(12-4m)x-9=0 x=(9-m²)/(12-4m)因为 12-4m不...