#### esuahcdss12

##### New member

- Joined
- Nov 26, 2017

- Messages
- 2

I just started to learn this subject and I got how to prove and to find infimum and supermium.

but I have problem with 1 question, i got now idea where to start and how to prove it.

this is the question:

Given two bounded sets X and Y , which their element are non negative REAL numbers,

so - X*Y = {x*y : x in X, y in Y},

prove that:

a) inf{X*Y} = inf X* inf Y

b)sup{X*Y} = supX *supY

Can anyone help please?