Question Number 391 by 123456 last updated on 25/Jan/15
$${f}\left[{f}\left({x}\right)\right]={f}\left({x}^{\mathrm{2}} \right) \\ $$
Answered by prakash jain last updated on 27/Dec/14
$$\mathrm{The}\:\mathrm{equation}\:\mathrm{above}\:\mathrm{implies} \\ $$$${f}\left({x}\right)={x}^{\mathrm{2}} \\ $$