If function f satisfies the relation $\mathrm{f}\left(\mathrm{x}\right)\times \mathrm{f}\text{'}\left(-\mathrm{x}\right)=\mathrm{f}\left(-\mathrm{x}\right)\times \mathrm{f}\text{'}\left(\mathrm{x}\right)$ for all x, and f(0) = 3, and if  f(3) =3, then the value of f(-3) is ____