Questions: The rational function R(x)=(x^3-8)/x has a/an [Select ] " asymptote.
Choose the best answer.
[Select] no
horizontal only a vertical
oblique
slant
Transcript text: The rational function $\mathbb{R}(x)=\frac{x^{3}-8}{x}$ has $\mathrm{a} / \mathrm{an}$ [Select ] " asymptote.
Choose the best answer.
[Select] no
horizontal only a vertical
oblique
slant
Solution
Solution Steps
To determine the type of asymptote for the rational function \(\mathbb{R}(x) = \frac{x^3 - 8}{x}\), we need to analyze the degrees of the polynomial in the numerator and the denominator. The degree of the numerator is 3, and the degree of the denominator is 1. Since the degree of the numerator is greater than the degree of the denominator by exactly one, the function has an oblique (or slant) asymptote. We can find the equation of the oblique asymptote by performing polynomial long division on the numerator by the denominator.
Step 1: Identify the Function
We are given the rational function
\[
\mathbb{R}(x) = \frac{x^3 - 8}{x}.
\]
Step 2: Determine the Degrees
The degree of the numerator \(x^3 - 8\) is 3, and the degree of the denominator \(x\) is 1. Since the degree of the numerator is greater than the degree of the denominator by exactly one, we expect an oblique (or slant) asymptote.
Step 3: Perform Polynomial Long Division
To find the oblique asymptote, we perform polynomial long division of \(x^3 - 8\) by \(x\):
Divide the leading term \(x^3\) by \(x\) to get \(x^2\).
Multiply \(x^2\) by \(x\) to get \(x^3\).
Subtract \(x^3\) from \(x^3 - 8\) to get \(-8\).
The remainder is \(-8\), which does not affect the asymptote.
Thus, the quotient from the division is
\[
x^2.
\]
Final Answer
The oblique asymptote of the function \(\mathbb{R}(x)\) is