186k views
1 vote
Identify the domain and the range of the function

Identify the domain and the range of the function-example-1
User Pengdu
by
4.9k points

1 Answer

4 votes

So the first graph is Radical/Irrational Graph and the second is Parabola/Quadratic Graph.

You can find the domain by looking at the x-axis and for the range, look at the y-axis. That means all of x-axis is the domain and all of y-axis is the range.

From the first graph, the domain is from -2 to +infinite. But because there's a colored dot, it's either ≥ or ≤.

But because -2 is less than + infinite, we use ≤ instead. Thus, x ≥ -2

Remember that x-values can't be equal to infinite. So we use < instead since there's no x-values that are equal to ∞.

Or we can write in interval notation as [-2,+∞) for symbol "[ or ]" is equal to ≤ or ≥ and ") or (" is equal to > or <

Again, the domain for the first graph is x ≥ -2 or x ∈ [-2, +∞)

And the range, look at the y-axis. Because we can substitute x from -2 to less than ∞, that means the range is from -1 because when x = -2 then x = -1 to + infinite.

Therefore, the range is y ≥ -1 or y ∈ [-1, +∞)

Now for the second graph. Look at the x-axis to find the domain. We notice that the colored dot is at x = -3 and the one with white dot is at x =2. The one without the color or white dot is > or < while the colored one is ≥ or ≤.

So the domain is -3 ≤ x < 2 or x ∈ [-3, 2)

For range, look at the y-axis. Notice that the colored dot is at y = -5 and the maximum point is at y =4. The y =4 is still in the domain so the range still applies to the maximum point.

Therefore the range is -5 ≤ y ≤ 4 or y ∈ [-5, 4]

User Nipun Tyagi
by
5.2k points