A graphing calculator can be very helpful for this.
14. Please note that the axis of symmetry will be halfway between the roots. If the roots are -5 and +1, the axis of symmetry will be x = (-5+1)/2 = -2.
It is usually convenient for graphing to plot points within a few units either side of the vertex.
The domain of any polynomial is "all real numbers." The range of a quadratic will be limited in one direction by the vertex. Here, it is all real numbers less than or equal to 9.
15. See the 2nd graph.
16. See the 3rd graph.
