Default [Q] Are my phone is still under warranty?

Hi everybody. I recently buy my note 3 from someone who sell it on internet. That person tell me that the phone is new and that he got only one day use. I have the box, all the accessory and I also got the bill.

When I go into download mode, I can see that the Knox Warranty Void is 0x1. Does it means that my phone have been rooted (because I don't see no trace of root) and also I want to know if my phone is still under warranty?

Thank you

PS: Sorry if my english is not perfect. I'm from Quebec and i'm working hard to be billingual