Show that if the graph of a twice-differentiable function (x) has an inflection point at x =

Show that if the graph of a twice-differentiable function ƒ(x) has an inflection point at x = a, then the linearization of ƒ at x = a is also the quadratic approximation of ƒ at x = a. This explains why tangent lines fit so well at inflection points.