Question Number 142936 by Snail last updated on 07/Jun/21
$${Find}\:{all}\:{real}\:{values}\:{of}\:{a}\:\:\:{such}\:{that}\:\:{f}\left({x}\right)=\frac{{x}^{\mathrm{2}} +{ax}+\mathrm{1}}{{x}^{\mathrm{2}} +{x}+\mathrm{1}}\:\: \\ $$$${is}\:{surjective}\:\:{f}\::\boldsymbol{\Re}\Rightarrow\Re \\ $$