Question Number 177859 by neinhaltsieger369 last updated on 10/Oct/22
Answered by a.lgnaoui last updated on 10/Oct/22
$${anser}\:{ix}\left({c}\right)\:\:\:\:\frac{\mathrm{3}}{\mathrm{7}} \\ $$$$\partial{W}=\frac{\partial{W}}{\partial{x}}\partial{x}+\frac{\partial{W}}{\partial{y}}\partial{y}+\frac{\partial{W}}{\partial{z}} \\ $$$$=\frac{\mathrm{1}}{\:\left(\sqrt{{x}^{\mathrm{2}} +{y}^{\mathrm{2}} +{z}^{\mathrm{2}} \:}\:\right)^{\mathrm{2}} }\left({x}+{y}+{z}\right)=\frac{{x}+{y}+{z}}{\:{x}^{\mathrm{2}} +{y}^{\mathrm{2}} +{z}^{\mathrm{2}} } \\ $$$$\partial{W}_{\left(\mathrm{1},\mathrm{2},\mathrm{3}\right)} =\frac{\mathrm{6}}{\mathrm{14}}=\frac{\mathrm{3}}{\mathrm{7}} \\ $$
Commented by neinhaltsieger369 last updated on 10/Oct/22
$$\:\boldsymbol{\mathrm{Gracias}} \\ $$