The first one should be 8 since you want 0/0 here.
I would use the squeeze/turkey sandwich theorem here.
f is either the square or 0. Hence
Third one... so for all x.
Here's I'm thinking of x as a natural number heading towards infinity, but I don't think it matters where we head.
Iin the last one we need
, which seems to be 15.
It's 2am and I'm done for tonight.
With a=2 we have