Westonci.ca is the ultimate Q&A platform, offering detailed and reliable answers from a knowledgeable community. Connect with a community of experts ready to help you find accurate solutions to your questions quickly and efficiently. Our platform offers a seamless experience for finding reliable answers from a network of knowledgeable professionals.

The image of a point is given by the rule [tex]r_{y=-x}(x, y) \rightarrow (-4,9)[/tex]. What are the coordinates of its pre-image?

A. [tex](-9,4)[/tex]
B. [tex](-4,-9)[/tex]
C. [tex](4,9)[/tex]
D. [tex](9,-4)[/tex]


Sagot :

To find the pre-image of a point under the reflection rule \( r_{y=-x} \), let's carefully analyze the reflection over the line \( y = -x \).

When a point \((x, y)\) is reflected over the line \( y = -x \):
1. The x-coordinate of the new point will be the negative of the y-coordinate of the original point.
2. The y-coordinate of the new point will be the negative of the x-coordinate of the original point.

Given that the reflected point (image) is \((-4, 9)\), we need to determine the coordinates of the original point (pre-image) that produced this reflection.

Let's solve this step-by-step:

1. Let's denote the pre-image coordinates by \((x, y)\).
2. According to the reflection rule \( r_{y=-x} \), the pre-image point \((x, y)\) will transform as:
[tex]\[ (x, y) \rightarrow (-y, -x) \][/tex]
3. The given image point is \((-4, 9)\). Therefore, we set up the equations based on the rule:
[tex]\[ (-y, -x) = (-4, 9) \][/tex]

4. From this, we can extract two equations:
[tex]\[ -y = -4 \quad \Rightarrow \quad y = 4 \][/tex]
[tex]\[ -x = 9 \quad \Rightarrow \quad x = -9 \][/tex]

So, the coordinates of the original point (pre-image) are \((-9, 4)\).

Comparing this with the provided options:
- \((-9, 4)\)
- \((-4, -9)\)
- \((4, 9)\)
- \((9, -4)\)

The correct answer is:
[tex]\[ (-9, 4) \][/tex]
We hope this was helpful. Please come back whenever you need more information or answers to your queries. Thank you for choosing our platform. We're dedicated to providing the best answers for all your questions. Visit us again. Westonci.ca is your trusted source for answers. Visit us again to find more information on diverse topics.