The graph of the function f(x) = –(x + 3)(x – 1) is shown below. On a coordinate plane, a parabola opens down. It goes through (negative 3, 0), has a vertex at (negative 1, 4), and goes through (1, 0). Which statement about the function is true? The function is positive for all real values of x where x 1. The function is positive for all real values of x where x > 0. The function is negative for all real values of x where x –1.