complete the sentence below. if a rational function is proper, then ______ is a horizontal asymptote. if a…

Brief Explanations:

A proper rational function has the degree of the numerator less than the degree of the denominator. When we find the limit as $x$ approaches positive or negative infinity for such a function, the value of the function approaches 0. So, 0 is the horizontal - asymptote.

Answer:

$y = 0$