(1)[f(x)]^2=x[g(x)]^2+x[h(x)]^2,f,g,h∈R(x),x<0时左边>=0>=右边，∴f(x)=0,[g(x)}^2+[h(x)]^2=0,∴g(x)=h(x)=0.无法证明x>=0时上述结论也成立。(2)不成立。
