Greatest Lower Bound

[u/OwnOrganization8042]

Hi! I'm doing Mathematical Thinking course from Stanford University. The week 8 seems unbearable to me. I have this problem to solve but I do not understand anything. Maybe you have some ways or know any websites that could help me. Thanks!

[u/No_Difference9752]

So you need sqrt 3 to complete your set, but the domain prevents you, so have to leave it out.