$\text{ Let }\mathrm{f}\text{ be an invertible function from }\mathrm{R}\to \mathrm{R}\text{ satisfying the equation }{\mathrm{f}}^3\left(\mathrm{x}\right)-\left({\mathrm{x}}^3+2\right){\mathrm{f}}^2\left(\mathrm{x}\right)+\left(2{\mathrm{x}}^3+1\right)\mathrm{f}\left(\mathrm{x}\right)-{\mathrm{x}}^3=0$

$\text{ Then the value of }f\text{'}\left(8\right)\times \left(f^{-1}\right)\text{'}\left(8\right)\text{, is : }$