Use conjugate roots and a reciprocal substitution

The complex numbers $z_1=2$ and $z_2=i$ are roots of $z^3+Az^2+Bz+C=0$, where $A,B,C$ are real.

(i) State the third root and find $A,B,C$.3 marks

(ii) Hence, with a suitable substitution, find the roots of $2w^3-w^2+2w-1=0$.3 marks