Matplotlib in Tensorflow Jupyter Notebook
Add import sys and sys.executable to the top of your notebook, then run it. This shows you the directory of the running kernel. With this information, from a new command-line (not a Python console) run C:\path\to\python.exe -m pip install matplotlib
In Anaconda Navigator, I switched to running applications on tensorflow and installed jupyter 5.6.0. I then open up a Python3 notebook. I then import tensorflow, keras and numpy without issue. Then when I try to import matplotlib, the notebook says ImportError: No module named 'matplotlib'. 
I tried running the following command in my anaconda prompt in both base and after activating tensorflow: pip3 install matplotlib
And it says: 
(tensorflow) C:\Users\danie>pip3 install matplotlib
Requirement already satisfied 
for 7 different lines. What am I doing wrong?