Chapter 4 Quadratic Functions and Factoring - 4.10 Write Quadratic Functions and Models - Guided Practice for Examples 1, 2, and 3 - Page 310: 3

$f(x)=0.25(x+2)(x-5)$.

If the x-intercepts of a graph are $a,b$, then the function has the form $f(x)=k(x-a)(x-b)$. The x-intercepts are -2, 5, hence the quadratic function becomes $f(x)=k(x+2)(x-5)$. The point (6,2) is on the graph, hence if we plug in the values we get $2=k(8)(1)$ and k=0.25. $f(x)=0.25(x+2)(x-5)$.