Question Number 20616 by virus last updated on 29/Aug/17
$${x}={r}\mathrm{cos}\:\theta\mathrm{cos}\:\emptyset,{y}={r}\mathrm{sin}\:\theta\mathrm{sin}\:\emptyset,{z}=\mathrm{sin}\:\theta \\ $$$${then}\:{prove}\:{that}\:{x}^{\mathrm{2}} +{y}^{\mathrm{2}} +{z}^{\mathrm{2}} ={r}^{\mathrm{2}} \\ $$
Commented by virus last updated on 01/Sep/17
$${please}\:{solve}\:{this} \\ $$