Answer
a) $y=0$
b) No horizontal asymptote.
c) $y=2$
Work Step by Step
First we check if we can simplify the given rational expressions.
We notice that none of them can be simplified.
We find the horizontal asymptotes of rational functions using this rule:
If $N$ is the degree of the numerator and $D$ the degree of the denominator, then:
i) If $N>D$: No horizontal asymptote exists.
ii) If $N=D$, there is a horizontal asymptote $y=\frac{a_n}{b_n}$, where $a_n$ and $b_n$ are the leading coefficients of the numerator and denominator.
iii) If $N
