Final answer:
To find the horizontal asymptote of a rational function, use the rules that compare the degrees of the numerator and the denominator.
Step-by-step explanation:
The correct answer to finding the horizontal asymptote of a rational function is D. Use one of the 3 rules. These rules pertain to the degrees of the numerator (let's call it N) and denominator (let's call it D) of the rational function represented as N(x)/D(x):
- If the degree of N is less than the degree of D, the horizontal asymptote is y = 0.
- If the degree of N is equal to the degree of D, the horizontal asymptote is y = the coefficient of the highest-degree term of N divided by the coefficient of the highest-degree term of D.
- If the degree of N is greater than the degree of D, the function does not have a horizontal asymptote (it may have an oblique or slant asymptote instead).
Options A, B, and C do not provide the correct method for finding horizontal asymptotes.