We will answer the question given in the picture.
We can see from the question a part of a linear function, and we can see an open circle at the point (4, -2). We can also see that the arrow of the linear function indicates that the function continues infinitely.
To find the domain and the range of the function we need to remember that:
• The domain of a function is, roughly speaking, all of the values for which the function is defined. In general, is represented by all of the values of x for which this function is defined.
,
• The range of a function is, roughly speaking, all the values that the variable y, the dependent variable, takes for each of the values of the independent variable, x.
Therefore, if we check the graph, we have:
The domain of the function
1. The values for x are not defined for x = 4 (we can see a small open circle at the point (4, -2). However, the values for x continue infinitely after that. Therefore, the domain of the part shown is as follows:
[tex]\text{ Domain=}x>4[/tex]
And we can say that the domain of the function is for all of the values greater (not equal to x = 4) to positive infinity. We can write this in interval notation as follows:
[tex]\text{ Domain=}(4,\infty)[/tex]
The range of the function
We can check from the graph that the values for y start from y = -2. However, y = -2 is not included since we have a small open circle that indicates that (see above).
Therefore, the range of the function is given by:
[tex]y<-2[/tex]
And we can say that the values of the range are less than y = -2 (not equal), and they are all smaller than y = -2 (for instance, -3, -4, -5.001, -10.222, and so on). The latter values are less than y = -2. We can write this in interval notation as follows:
[tex]\text{ Range=}(-2,-\infty)_[/tex]
Therefore, in summary, we can say that:
1. The inequality to represent the domain of the part shown is x > 4. It means that the domain is those values of the independent variable greater than x = 4 (not equal to 4), and these values extend to positive infinity.
2. The inequality to represent the range of the part shown is y < -2. It means that the range is those values of the dependent variable less than y = -2 (not equal to y = -2), and these values extend to negative infinity.
