We need to see the graph to answer this question properly. Or you can describe the graph, for example where the vertex of this function is Do try.

Here is a discussion which may help:

https://www.qalaxia.com/viewDiscussion?messageId=5e4c1435f476f9779a06c052

I found an answer from math.stackexchange.com

Find a real **function f**:R→R such that **f**(**f**(**x**))=−**x**?

An important piece of information is: Theorem: **f** is not continuous. Proof: Observe
that **f** is invertible, because. **f**(**f**(**f**(**f**(**x**))))=**f**(**f**(**−x**))=**x**. and so **f**∘**f**∘**f**=**f−1**.

For more information, see Find a real **function f**:R→R such that **f**(**f**(**x**))=−**x**?

I found an answer from math.stanford.edu

Linear Transformations

to say: the level set of the **function F**(**x**, y) = x2 +y2 at height **1**. That is ... **x** = **f**(t) y =
**g**(t). Surfaces in R3: Three descriptions. (**1**) **Graph** of a **function f** : R2 → R. (That
is: z = **f**(**x**, y).) ... The linear transformation defined by **D** has the following effect:
Vectors are. ... Example **1**: Let A be a (3 × 2)-matrix, and let **B** be a (2 × 4)-matrix.

For more information, see Linear Transformations