Sketch a graph of the polynomial function with the following characteristics.
fis decreasing on the intervals (-∞, -1.5) and (2.5, 0); f is increasing on the interval
(-1.5, 2.5).
f(x) > 0 on the intervals (-∞, -3) and (1, 4); f(x) <0 on the intervals (-3, 1) and (4, ∞).