Find functions $f$ and $g$ so that $f$@$g=H.H(x)=\frac{1}{x^2-8}f(x)=\frac{1}{x^2}-9$;$g(x)=\frac{1}{x}f(x)=x^2-8$;$g(x)=\frac{1}{x}f(x)=\frac{1}{x}$;$g(x)=\frac{1}{x^2}-9f(x)=\frac{1}{x},g(x)=x^2-8$