Eh? Those formulas are indeed quadratic.
A quadratic expression is a polynomial involving a squared term (and no higher exponent). That's actually a correct way to describe these formulas, since they do include an X squared term if you multiply them out. Using Truth as an example, each graph would be a parabola (and bottom out at MA=0) if you graphed the formulas out on, say, a graphing calculator (where MA would be the X-axis and would span negative to positive MA), but since you can't have negative MA, we don't normally worry about the negative MA part of the graph. Nonetheless, those formulas are quadratic (and not exponential - exponential means the exponent itself is the variable; something like 2^MA, which would start slow but grow to insane levels extremely fast).