Question Number 52240 by aghoelvis511@gmail.com last updated on 05/Jan/19
$${i}={what}\:{in}\:{complex}\:{number}. \\ $$
Commented by Tawa1 last updated on 05/Jan/19
$$\boldsymbol{\mathrm{i}}\:\:=\:\:\boldsymbol{\mathrm{iota}} \\ $$$$ \\ $$$$\boldsymbol{\mathrm{i}}\:\:=\:\:\boldsymbol{\mathrm{cos}}\:\frac{\pi}{\mathrm{2}}\:+\:\boldsymbol{\mathrm{i}}\:\boldsymbol{\mathrm{sin}}\:\frac{\pi}{\mathrm{2}} \\ $$$$\mathrm{where}\:\:\:\:\pi\:=\:\mathrm{180}° \\ $$