What type of function does this graph show?

Answer:
(negative) quadratic function
Step-by-step explanation:
Quadratic function: polynomial function of degree 2, represented graphically by a parabola.
Standard form of a quadratic function: [tex]f(x)=ax^2+bx+c[/tex]
If the leading coefficient ([tex]a[/tex]) is positive, the parabola opens upwards (U-shaped)
If the leading coefficient ([tex]a[/tex]) is negative, the parabola opens downwards (∩-shaped)