where is the link?
Scroll back 5 posts and click on it. It’s the inset text, in blue font that says “Math for Machine Learning FAQ”.
I have shared the steps from the link I shared earlier to get fresh copy of notebook. Also I highly suggest before moving to any new course get familiar with how to use discourse forum by going through FAQ section in detail.
HOW TO GET A FRESH COPY OF A NOTEBOOK IN COURSERA PLATFORM
Click file, then select open. You will find all the files related to the assignment. Here if you have saved a copy of your notebook with renaming other than what was mentioned. Then go ahead and delete the assignment notebook by selecting the particular notebook.
Once deleted, you will find 404 not found image on your browser. Then close the browser.
Open the assignment page again, when you open you will find 404 not found.
At this time, click 
on the right hand top corner Before Grades, where you will find Reboot. Click reboot.
Then click the same on the right hand top corner, then click Get latest version and then Update lab.
I have completed my specialization
Thank you soooo much for your kind guidance
great. please go through this section
this has community guidelines, how to use forum, how to post, how to create topic, what not to do, what you could do, everything. So by next course you are more comfortable getting your issue resolved in case you have.
Keep Learning!
Regards
DP