Question Number 223525 by Nicholas666 last updated on 27/Jul/25
$$ \\ $$$$\:\:\:\:{I}\:=\:\int_{\mathrm{0}} ^{\mathrm{2}\pi} \int_{\mathrm{0}} ^{\mathrm{2}\pi} \int_{\mathrm{0}} ^{\mathrm{2}\pi} \:\mid\:\mathrm{cos}\:{x}\:+\:\mathrm{cos}\:{y}\:+\:\mathrm{cos}\:{z}\:\:\mid\:\:{dxdydz}\:\:\:\:\:\:\:\: \\ $$$$ \\ $$