设幂函数f(x)=x^a
f(根号3/3)=(根号3/3)^a=3根号3
(3^(-1/2))^a=3^(3/2)
3^(-a/2)=3^(3/2)
-a/2=3/2
a=-3
故f(x)=x^(-3)=1/x^3