I just found Matlab (2016a) put a 2.5 Gb installation files that it fetched during the installation in the root home directory (Linux mint 18), under `/root/Downloads/MathWorks`. I guess it is probably because I use `sudo` for installation. 

My question is:

1. Is it normal that program store information when user executes it with `sudo`?
2. Can I delete the file under `/root/Downloads`? (My limited Linux knowledge told me do not touch anything in the `/root` folder)