Answer:
-1 and 3
Step-by-step explanation:
The roots of the quadratic function can be determined by [tex]f(x')=0[/tex] where x' is the roots of the quadratic function. In that graph, x = -1 and x = 3 makes the value of f(-1) = 0 and f(3) = 0. So, x = -1 and x = 3 are the roots of the f(x).
