Suppose f(2)=8\displaystyle {f{{\left(-{2}\right)}}}=-{8}, and f(2)=27\displaystyle {f}'{\left(-{2}\right)}=-\frac{{2}}{{7}}.

(f1)(8)=\displaystyle {\left({f}^{{-{{1}}}}\right)}'{\left(-{8}\right)}=  

Write the equation of the tangent line to f1(x)\displaystyle {{f}^{{-{{1}}}}{\left({x}\right)}} at x=8\displaystyle {x}=-{8}.
y=\displaystyle {y}=