The graph has a vertex at (3, -2). It extends upward from there linearly at a slope of -1 to the left and 1 to the right. It is the graph of an absolute value function. If we assume it keeps extending upwards the domain is all real numbers. (which is what i would assume even though there's no arrows it doesn't have decipherable endpoints). The range is y ≥ -2 with y -intercept (0,1), and x-intercepts: (5,0) & (1,0).
To write the equation for this function, I would acknowledge that it is the translation of the graph of the standard absolute value function: f(x) = |x| ; right 3 and down 2. Which would be to subtract 3 from x and subtract 2 from the end.
f(x) = |x - 3| - 2