Question Number 185933 by aymanadnan last updated on 30/Jan/23
Answered by qaz last updated on 30/Jan/23
$${dV}=\mathrm{2}\left({y}^{\mathrm{2}} −{x}^{\mathrm{2}} \right){d}\left({y}^{\mathrm{2}} −{x}^{\mathrm{2}} \right)=\mathrm{4}\left({y}^{\mathrm{2}} −{x}^{\mathrm{2}} \right)\left({ydy}−{xdx}\right) \\ $$$$\Rightarrow{V}_{{x}} =\mathrm{4}{x}\left({x}^{\mathrm{2}} −{y}^{\mathrm{2}} \right)\:\:\:\:{V}_{{y}} =\mathrm{4}{y}\left({y}^{\mathrm{2}} −{x}^{\mathrm{2}} \right) \\ $$$$\Rightarrow{yV}_{{x}} +{xV}_{{y}} =\mathrm{0} \\ $$