Update sig_sys_ex_09.tex #36

	# this file was taken from the lecture
	# Sascha Spors: "Continuous- and Discrete-Time Signals and Systems - Theory and Computational Examples"
	# see
	# https://github.com/spatialaudio/signals-and-systems-lecture/blob/master/.github/workflows/notebook_ci.yml
	# executes all cells (e.g. numerical examples) in all notebooks
	# by using sphinx with the nbsphinx extension

	name: Integration Test

	on:
	push:
	pull_request:

	schedule:
	- cron: '30 1 1,15 * *'

	jobs:
	linux_py38:
	runs-on: ubuntu-latest

	steps:
	- uses: actions/checkout@v3
	- uses: actions/setup-python@v3
	with:
	python-version: 3.8
	- run: sudo apt-get install pandoc
	- run: pip install -r requirements.txt
	- run: pip install -r ci/requirements.txt
	- run: python -m sphinx . _build/ -b html

	linux_py39:
	runs-on: ubuntu-latest

	steps:
	- uses: actions/checkout@v3
	- uses: actions/setup-python@v3
	with:
	python-version: 3.9
	- run: sudo apt-get install pandoc
	- run: pip install -r requirements.txt
	- run: pip install -r ci/requirements.txt
	- run: python -m sphinx . _build/ -b html

Provide feedback