How to find the domain and range?
1 Answer
For 30, D: {x| x > -4} & R: {y| y ≤ 5}
For 31, D: {x| -4 ≤ x ≤ 5} & R: {y| -5 ≤ y ≤ 9}
Explanation:
Remember that your domain is your x-values and your range is your y-values. I'm assuming that the axes are a scale of 1.
Let's start with 30. The domain is x > -4. Note that it is "greater than". There is a "hole" in the graph at x = -4, so that point (-4,1) is not included in the domain. Since the line is headed to the right, the x-values will be increasing. This makes it x > -4. The range is y ≤ 5. The greatest y-value on the graph is at y = 5. This point (0,5) is included since there is no "hole" at that point. Note that 1 is part of the range since (3,1) is a point on the line.
Next to 31. The domain is restricted to between -4 and 5 (both inclusive). The range is restricted to between -5 and 9 (both inclusive). Remember that when you are dealing with ellipses and circles, your domain and range are restricted to between two inclusive values.
