Question Number 77178 by jagoll last updated on 04/Jan/20
$$ \\ $$$${given}\:\mathrm{cos}^{−\mathrm{1}} \left({x}\right)+\mathrm{cos}^{−\mathrm{1}} \left({y}\right)+\mathrm{cos}^{−\mathrm{1}} \left({z}\right)=\pi \\ $$$${and}\:{x}+{y}+{z}=\frac{\mathrm{3}}{\mathrm{2}} \\ $$$${prove}\:{that}\:{x}\:=\:{y}\:=\:{z}\:. \\ $$
Answered by john santu last updated on 04/Jan/20
Commented by jagoll last updated on 04/Jan/20
$$\mathrm{thanks}\:\mathrm{you} \\ $$