Since area is length times width, it would be the factors of the equation for the area.
X2+11x+28 factors into...
Length is x+7 so...
Width is x+4
Answer: See description below.
The residuals are the differences between the predicted values and the actual values. You will need to make a scatter plot of each difference.
Here are the five points that you will need to plot:
20 - 21 = -1 (1, -1)
17 - 16 = 1 (2, 1)
9 - 10 = -1 (4, -1)
6 - 5 = 1 (5, 1)
2 - 2 = 0 (6, 0)
One important feature of the parabola is that it has an extreme point, called the vertex. If the parabola opens up, the vertex represents the lowest point on the graph, or the minimum value of the quadratic function.
