A little bit about this: for the economy aspect of a plugin that I'm writing, I need to determine the price of something based on 1) the initial price and 2) a maximum price.
With this, if we create a parabola (and cut it off where x >= 0) with the axis of symmetry as 0 (x = 0), we can get this value. Since the parabola is dynamic based on the item needing to be charged, we have to create something to return the y of a point when given the x.
Our two points for testing were (0, 100) and (2500, 6000). Where 100 is base, 6000 is max, 2500 is maxLevel and point is the point we want to get. HOWEVER with the idea that this parabola starts at 0, a good idea is to treat this as