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 negative for all real values of x where x < –3 and 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 < –3 or x > –1.