Question
What happens to the x-intercepts of the function y=x2−9
when the graph is reflected over the x-axis?(1 point)
Responses
There are no x-intercepts.
There are no x-intercepts.
The x-intercepts get shifted to the right 9 units.
The x-intercepts get shifted to the right 9 units.
The x-intercepts stay the same.
The x-intercepts stay the same.
The x-intercepts get shifted down 9 units.
when the graph is reflected over the x-axis?(1 point)
Responses
There are no x-intercepts.
There are no x-intercepts.
The x-intercepts get shifted to the right 9 units.
The x-intercepts get shifted to the right 9 units.
The x-intercepts stay the same.
The x-intercepts stay the same.
The x-intercepts get shifted down 9 units.
Answers
GPT-4o mini
To determine the effect on the x-intercepts of the function \( y = x^2 - 9 \) when the graph is reflected over the x-axis, we first need to find the x-intercepts of the original function.
The x-intercepts occur when \( y = 0 \):
\[
x^2 - 9 = 0
\]
This can be factored:
\[
(x - 3)(x + 3) = 0
\]
So the x-intercepts are \( x = 3 \) and \( x = -3 \).
When the graph is reflected over the x-axis, the new function becomes:
\[
y = -(x^2 - 9) = -x^2 + 9
\]
To find the new x-intercepts, we set \( y = 0 \):
\[
-x^2 + 9 = 0
\]
Rearranging gives:
\[
x^2 = 9
\]
Taking the square root of both sides, we find:
\[
x = 3 \quad \text{and} \quad x = -3
\]
Thus, when the graph is reflected over the x-axis, the x-intercepts remain the same: \( x = 3 \) and \( x = -3 \).
Therefore, the correct response is:
**The x-intercepts stay the same.**
The x-intercepts occur when \( y = 0 \):
\[
x^2 - 9 = 0
\]
This can be factored:
\[
(x - 3)(x + 3) = 0
\]
So the x-intercepts are \( x = 3 \) and \( x = -3 \).
When the graph is reflected over the x-axis, the new function becomes:
\[
y = -(x^2 - 9) = -x^2 + 9
\]
To find the new x-intercepts, we set \( y = 0 \):
\[
-x^2 + 9 = 0
\]
Rearranging gives:
\[
x^2 = 9
\]
Taking the square root of both sides, we find:
\[
x = 3 \quad \text{and} \quad x = -3
\]
Thus, when the graph is reflected over the x-axis, the x-intercepts remain the same: \( x = 3 \) and \( x = -3 \).
Therefore, the correct response is:
**The x-intercepts stay the same.**