The function f(x) = x^2 + 6x + 8.

The graph of the function is

The vertex is (-3, -1), the axis of symmetry is x = -3. The x-intercept is -2 and -4, the y intercept is 8, the domain is R, the range is [-1, inf.]

The function is increasing in {-3, inf.} and decreasing in {-inf., 3}