To calculate this limit, we divide both numerator and denominator by , n is the highest power of x in the denominator. In , the highest power of x is 2. So n = 2. We'll divide both numerator and denominator by .
When x goes to , the fractions , , , ... etc will approach 0.
So, the limit becomes . That means the horizontal asymptote is the line y=0, which is also called the x axis.