1和3
解:由题意知,当x=1时,f(x)=1,g(x)=3,f[g(x)]=f(3)=1,g[f(x)]=g(1)=3,
满足f[g(x)]<g[f(x)].
当x=2时,f(x)=3,g(x)=2,f[g(x)]=f(2)=3,g[f(x)]=g(3)=1,
不满足f[g(x)]<g[f(x)].
当x=3时,f(x)=1,g(x)=1,f[g(x)]=f(1)=1,g[f(x)]=g(1)=3,
满足f[g(x)]<g[f(x)].
综上,当x=1时,或当x=3时,满足f[g(x)]<g[f(x)].