Question

Help Solve Domain and Range

Answer 1

You would likely benefit far more from learning the definitions of "domain" and "range" than from being given the domain and range in each of these cases.

The domain of a function includes all values of the independent variable for which the function is defined (that is, for which there is a graph). In Case 1, x can have any real value, and so the domain is (-infinity, infinity).

The range of a function includes all values that the dependent value can have (that is, for which there is a graph). In Case 1, y can take on any real value, and so the range is (-infinity, infinity).

Contrast this case to Case 2. Here, y has only ONE value, so the range is simply y=2, or {2}. x can take on any value, so the domain is (-infinity, infinity).

Answer 2

Domain and Range are simply the areas where a graph exist.

Domain is in what values of X a Y value exists for, and Range is what vales of Y existences

For example, lets look at number 1:

looking at the graph, we can see that the Y values will all be taken, so the Range is -∞<y<∞

We can also see that all the x values will also be used, so -∞<x<∞

Lets look at 6

As we can see only some of the values are used, and only some x values are legal.

The domain is -1<x<8

and the range is 1<y<7

Lets look at question 2:

as we can see, every x value is used, so the domain is -∞<x<∞

but the range is locked at 2, so the range is simply y=2