#### Quadratic Functions Basics

- Quadratic functions is a type of function that has the form

y=a x^{2}+b x+c, where a,\ b,\ c \in R,\ a \neq 0

- Generally, the graph has a parabolic shape. If a>0, the graph will be open upwards (i.e. have a ‘smiley face’), and if a<0 it is open downwards (i.e. a ‘sad face’).

The right is an example of when a>0. For a case where a<0, simply flip the graph upside-down.