Wikipedia picture of the day on January 5, 2019: Circular paraboloid generated by z = − a ( x 2 + y 2 ) , a > 0 {\displaystyle z=-a(x^{2}+y^{2}),a>0} . http://bit.ly/2Vx0oI9
Cibo e viaggi / Food and travel notes by Livio Acerbo
Wikipedia picture of the day on January 5, 2019: Circular paraboloid generated by z = − a ( x 2 + y 2 ) , a > 0 {\displaystyle z=-a(x^{2}+y^{2}),a>0} . http://bit.ly/2Vx0oI9