Atable with four legs will sometimes wobble if one leg is shorter than the other three, but a table with three legs will not wobble. select the postulate that substantiates this fact.

The exact name of the postulate isn't coming to mind, but it's the postulate that any three points that are not on the same line will form a unique plane. A plane in mathematics is a flat surface that extends in all directions. 

)because it's going in order of the math sign

Do you need with the x value for the minimum? its always between the two intercepts for a parabola