What is a quadratic function?

1 Answer
Jul 3, 2018

General form of a quadratic function is f(x)=ax^2+bx+cf(x)=ax2+bx+c

Explanation:

Is a function with this general expresion and his characteristics are

a) Is defined for all x in RR. So Dom f = RR
b) Plot is a parabola with y-intercept y in (0, c)
c) The x-intercepts depends on the value of discriminant Delta defined by Delta=b^2-4ac

If Delta=0 only has a single x-intercept
if Delta >0 has two x intercept
if Delta<0 then has not any x-intercept

The branches of parabola are oriented upwards if a>0 or downwards if a<0
The general look of this type of functions is as follows (particular case of x^2-3x-3=f(x)
graph{x^2-3x-3 [-12.66, 12.65, -6.33, 6.33]}
Hop this helps