Question Number 7935 by tawakalitu last updated on 24/Sep/16
$${Find}\:\:{U}_{{x}} \:,\:\:{U}_{{xy}\:} \:,\:\:{U}_{{yy}} \:\: \\ $$$${Given}\:{that}\::\:\: \\ $$$${U}\:=\:{x}^{\mathrm{3}} {y}\:−\:{siny} \\ $$
Commented by prakash jain last updated on 26/Sep/16
$$\frac{\partial{U}}{\partial{x}}=\mathrm{3}{x}^{\mathrm{2}} {y} \\ $$$$\frac{\partial}{\partial{y}}\left(\frac{\partial{U}}{\partial{x}}\right)=\mathrm{3}{x}^{\mathrm{2}} \\ $$$$\frac{\partial{U}}{\partial{y}}={x}^{\mathrm{3}} −\mathrm{cos}\:{y} \\ $$$$\frac{\partial}{\partial{y}}\left(\frac{\partial{U}}{\partial{y}}\right)=\mathrm{sin}\:{y} \\ $$
Commented by tawakalitu last updated on 26/Sep/16
$${Is}\:{correct}\:{thank}\:{you}.\: \\ $$
Answered by prakash jain last updated on 02/Oct/16
$$\mathrm{answer}\:\mathrm{in}\:\mathrm{comments} \\ $$