Question Number 187605 by otchereabdullai last updated on 19/Feb/23
$$\:{what}\:{is}\:{the}\:{name}\:{of}\:{the}\:{shape}\:{whose} \\ $$$${graph}\:{is}: \\ $$$$\left({a}\right)\:{f}\left({x},{y}\right)=\sqrt{{x}^{\mathrm{2}} +{y}^{\mathrm{2}} } \\ $$$$\: \\ $$$$\:\left({b}\right)\:{f}\left({x},{y}\right)={x}^{\mathrm{2}} +{y}^{\mathrm{2}} \\ $$$$\: \\ $$$$\:\:\left({c}\right)\:{f}\left({x},{y}\right)=\sqrt{\mathrm{1}−{x}^{\mathrm{2}} −{y}^{\mathrm{2}} } \\ $$$$ \\ $$$$\:\:\:\:\left({d}\right)\:{f}\left({x},{y}\right)={x}^{\mathrm{2}} +{y}^{\mathrm{2}} −\mathrm{2}{x} \\ $$$$ \\ $$$$\:\:\:\:\left({e}\right)\:{f}\left({x},{y}\right)={xy} \\ $$