# Animation of Reflection over the line y=-x

**URL:** <https://cl.desmos.com/t/animation-of-reflection-over-the-line-y-x/7756>\
**Category:** Questions\
**Created:** [February 14, 2025, 7:00pm UTC](https://cl.desmos.com/t/animation-of-reflection-over-the-line-y-x/7756 "2025-02-14T19:00:16Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![Malgorzata\_Demkow](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/malgorzata_demkow/32/4659_2.png) [@Malgorzata\_Demkow](https://cl.desmos.com/u/Malgorzata_Demkow)\
**Post date:** [February 14, 2025, 7:00pm UTC](https://cl.desmos.com/t/animation-of-reflection-over-the-line-y-x/7756/1 "2025-02-14T19:00:16Z")

</div>

I was hoping someone could help me tweak slide 2 of this assignment to help me show the animation actually reflecting over the line y=-x.

I found an amazing animation of a reflection over y=x and was able to change it to what I needed in slide 1. On slide 2, I was able to get the figure to end up where I needed it to after the reflection, but visually it is not actually reflecting over the line the same way it does in slide 1. Any thoughts on what I can change to help make the visual more realistic?

> **[4.2 Practice 5 • Activity Builder by Desmos Classroom](https://teacher.desmos.com/activitybuilder/custom/67aa4e2ebf7d01599e6afa55)**
>
> by Malgorzata Demkow

---

<div class="post-metadata">

**Author:** ![Daniel\_Wekselgreene](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/daniel_wekselgreene/32/1819_2.png) [@Daniel\_Wekselgreene](https://cl.desmos.com/u/Daniel_Wekselgreene)\
**Post date:** [February 14, 2025, 10:45pm UTC](https://cl.desmos.com/t/animation-of-reflection-over-the-line-y-x/7756/2 "2025-02-14T22:45:15Z")

</div>

You can use a reflection function that directly maps original points to the reflected location. This way, as each original point moves to the ending location, it looks like the reflection is happening. Another benefit here is that you can use any original function. [[Copy of] 4.2 Practice 5 • Activity Builder by Desmos Classroom](https://teacher.desmos.com/activitybuilder/custom/67afc3ab122f8c40052901be)

---

<div class="post-metadata">

**Author:** ![Malgorzata\_Demkow](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/malgorzata_demkow/32/4659_2.png) [@Malgorzata\_Demkow](https://cl.desmos.com/u/Malgorzata_Demkow)\
**Post date:** [February 18, 2025, 12:18pm UTC](https://cl.desmos.com/t/animation-of-reflection-over-the-line-y-x/7756/3 "2025-02-18T12:18:01Z")

</div>

This is awesome! This will allow me to easily make several examples and work on a discovery activity with my students rather than just showing them the reflection. Thank you so much!

---

<div class="post-metadata">

**Author:** ![Daniel\_Wekselgreene](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/daniel_wekselgreene/32/1819_2.png) [@Daniel\_Wekselgreene](https://cl.desmos.com/u/Daniel_Wekselgreene)\
**Post date:** [February 18, 2025, 5:46pm UTC](https://cl.desmos.com/t/animation-of-reflection-over-the-line-y-x/7756/4 "2025-02-18T17:46:12Z")

</div>

No problem. I’ve made a bunch of [transformation/translation stuff](https://teacher.desmos.com/collection/602218dce01c180b7c285d86) over the past couple of years. Feel free to use anything you find interesting.