Question

I need help with this problem....

Answer 1

For the first look at what happens when approaching 0 from both the left and then the right. For the second one you can try the squeeze/sandwitch theorem

Answer 2

For the first I think the limit exists and is equal to 0. But for b I think the limit exists?

Answer 3

Yeah it should.
The approach usually goes (assuming well-behaved functions)
Find g and h such that g(x)<=f(x)<=h(x) for all x
That implies lim g(x) <= lim f(x) <= lim h(x)
Now if you can show lim lim g(x) = lim h(x) = L then f(x) is squeezed between them and you can conclude lim f(x) = L