(i)If $\displaystyle f(x)$ is a polynomial function $\displaystyle f:(0,\infty)\rightarrow(0,\infty)$satisfies the equation $\displaystyle f(f(x))=6x-f(x)$then find$\displaystyle f(17)$

(ii)If $\displaystyle f(x)$ is a polynomial function satisfying the condition such that $\displaystyle f(x^2+1)=(f(x))^2+1$ and that $\displaystyle f(0)=0$ then find$\displaystyle f(34).$