Hi, I have to match 6 functions with the equation for its horizontal asymptote, but I can't get it right.

I know at least 1 or more are wrong, can anyone tell me which, and how to solve it/them?

1. f(x) = (6x^3 + 2x + 1) / (2x^3 - 10x^2 + 13x +100)

y = 3

2. f(x) = arccot(x^2 - x^4)

y = pi

3. f(x) = arccot(x)

y = 0 and y = pi

4. f(x) = e^x

y = 0

5. f(x) = arctan(x)

y = pi/2 and y = -pi/2

6. f(x) = (6x^2 + 2x + 1) / (2x^3 - 10x^2 +13x +100)

none

Thanks!