I think it is not possible to find a certain equation from just a given points, it must have more given information because there is a lot of parabola pass throw (-1,1).
<span>they built 2.22 km per day I think</span>
Sphere = 4/3 πr^3
4/3 π (3^3) = 36π = 36*3.14 = 113.04 ft^3