1. (2 + e^1/x) / (2 - e^1/x)

What is the horizontal asymptotes?

2. f(x) = { sin x/x, x cant be 0

k, x = 0

In order for f(x) to be continous at x=0, the value of k must be ?

3. If a cant be 0, then Limit x->a (x^2 - a^2)/ (x^4 - a^4) is?

Help please? thankyou