Answer
a. See graph and explanations.
b. $(20,5, -120.5)$
c. see explanations.
d. see explanations.
Work Step by Step
a. See graph. In the standard 10x10 viewing window, we would see nothing. If we zoom out, we can see that the parabola has a local minimum at a vertex, but no maximum.
b. The vertex, or the relative minimum, can be found at $(20,5, -120.5)$
c. The graph can be viewed with a proper window as shown in the figure.
d. Knowing the position of the vertex, adjust the view window so that the x-coordinate of the vertex is centered, while the y-coordinate is at the lower part (for minimum) or upper part (for maximum). Enlarge the viewing window to include a good portion of the curve.
