Question Number 60717 by peter frank last updated on 24/May/19
Commented by Prithwish sen last updated on 25/May/19
$$=\begin{vmatrix}{\frac{\partial\mathrm{x}}{\partial\mathrm{r}}\:\:\:\:\:\frac{\partial\mathrm{x}}{\partial\theta}\:\:\:\:\:\frac{\partial\mathrm{x}}{\partial\emptyset}}\\{\frac{\partial\mathrm{y}}{\partial\mathrm{r}}\:\:\:\:\frac{\partial\mathrm{y}}{\partial\theta}\:\:\:\:\:\:\frac{\partial\mathrm{y}}{\partial\phi}}\end{vmatrix} \\ $$$$\:\:\:\:\begin{vmatrix}{\frac{\partial\mathrm{z}}{\partial\mathrm{r}}\:\:\:\:\:\frac{\partial\mathrm{z}}{\partial\theta}\:\:\:\:\:\:\frac{\partial\mathrm{z}}{\partial\phi}}\end{vmatrix} \\ $$$$=\mathrm{sin}\theta\mathrm{cos}\phi\left(\mathrm{r}^{\mathrm{2}} \mathrm{sin}^{\mathrm{2}} \theta\:\mathrm{cos}\phi\:\right)+\mathrm{sin}\theta\mathrm{sin}\phi\left(\mathrm{r}^{\mathrm{2}} \mathrm{sin}^{\mathrm{2}} \theta\:\mathrm{sin}\phi\right) \\ $$$$+\mathrm{cos}\theta\left(\mathrm{r}^{\mathrm{2}} \mathrm{sin}\theta\:\mathrm{cos}\theta\:\mathrm{cos}^{\mathrm{2}} \phi\:+\:{r}^{\mathrm{2}\:} {cos}\theta\:\mathrm{sin}\theta\:\mathrm{sin}^{\mathrm{2}} \theta\right) \\ $$$$=\mathrm{r}^{\mathrm{2}} \mathrm{sin}^{\mathrm{3}} \theta\left(\mathrm{cos}^{\mathrm{2}} \phi\:+\:\mathrm{sin}^{\mathrm{2}} \phi\right)\:+\mathrm{r}^{\mathrm{2}} \mathrm{sin}\theta\:\mathrm{cos}^{\mathrm{2}} \theta \\ $$$$=\mathrm{r}^{\mathrm{2}} \mathrm{sin}\theta \\ $$