Question Number 149137 by mathdanisur last updated on 03/Aug/21
$${if}\:\:\:{ctg}\boldsymbol{\alpha}\:=\:−\mathrm{2}\:\:\:{and}\:\:\:\frac{\mathrm{3}\pi}{\mathrm{2}}\:<\:\alpha\:<\:\mathrm{2}\pi \\ $$$${find}\:\:\:{sin}\boldsymbol{\alpha}\:=\:? \\ $$
Commented by liberty last updated on 03/Aug/21
$$\mathrm{sin}\:\alpha=−\frac{\mathrm{1}}{\:\sqrt{\mathrm{5}}} \\ $$