How to invert specific elements of array in-place?

I’m learning a data preprocessing course. I got a task in which I have to invert array elements in place. The teacher told me it has many approaches to do. I’m able to write one approach. Let me show you below:

#Loading library
import numpy as np
# Create an example 1D array
arr = np.array([1, 2, 3, 4, 5, 6, 7, 8, 9])
# Using indices and replacing it with invert values
arr[2:5] = -1 * arr[2:5]

Output: [ 1  2 -3 -4 -5  6  7  8  9]

In this approach, I used the concept of Indexing and broadcasting.
Can someone provide me with more techniques for achieving the same goal?

Explaination maybe needed:
My code create a 1D NumPy array with `9` elements. It then inverts the values of the elements between the indices `2` and `5` by multiplying them by `-1`, and replaces the original values with these inverted values in the original array. The result is printed to the console.