g(x) = ((2 * x) + 3) / x^(2)
g' = Derivative(g)
A = Intersect(g', xAxis, (-3.000000000000078, -5.789607476563327E-15))
f = OrthogonalLine(A, xAxis)
min = Intersect(g, f, (-3.000000000000078, -0.3333333333333333))
h: x = -9 / 2
flex = Intersect(g, h, (-4.5, -0.2962962962962963))
i = Tangent(flex, g)
g'' = Derivative(g, 2)
a = -0.2962962962962963 (slider from -5 to 5, step 0.1)
A1: -8 / 27
A2: -9 / 2