Question Number 198482 by Guillaume last updated on 20/Oct/23
$${x}^{\mathrm{2}} \:+\:\mathrm{1}\:=\mathrm{0}\:{resoudre}\:{dans}\:\mathbb{C} \\ $$
Answered by Frix last updated on 21/Oct/23
$${x}^{\mathrm{2}} =−\mathrm{1} \\ $$$${x}=\pm\mathrm{i} \\ $$
Answered by a.lgnaoui last updated on 21/Oct/23
$$\mathrm{x}^{\mathrm{2}} =−\mathrm{1}=\mathrm{i}^{\mathrm{2}} \:\:\:\: \\ $$$$\mathrm{x}=\left\{−\mathrm{i},+\mathrm{i}\right\} \\ $$$${Remarque}\:\:\:\:{i}^{\mathrm{6}} ={i}^{\mathrm{2}} =−\mathrm{1} \\ $$