(12) Given the function $f(x)=a^{x}-x(a>1)$.
(1) If $f(3)<0$, try to find the range of values for $a$;
(2) Write a set of numbers $a, x_{0}\left(x_{0} \neq 3\right.$, keep 4 significant digits), such that $f\left(x_{0}\right)<0$ holds.
(12) (1) $1<a<\sqrt[3]{3}$
(2) $a$ can take any value in $(1,1.442)$, and the corresponding $x_{0}$ will work