Asymptote Math Example 1

Follow the full solution, then compare it with the other examples linked below.

Example 1

easy
Find the vertical and horizontal asymptotes of f(x)=3xxโˆ’2f(x) = \dfrac{3x}{x - 2}.

Solution

  1. 1
    Vertical asymptote: set the denominator equal to zero. xโˆ’2=0โ‡’x=2x - 2 = 0 \Rightarrow x = 2. Since the numerator 3(2)=6โ‰ 03(2)=6 \neq 0, there is a vertical asymptote at x=2x = 2.
  2. 2
    Horizontal asymptote: compare degrees. Both numerator and denominator have degree 11. Divide leading coefficients: 31=3\frac{3}{1} = 3. Thus the horizontal asymptote is y=3y = 3.
  3. 3
    Verify by taking the limit: limโกxโ†’โˆž3xxโˆ’2=limโกxโ†’โˆž31โˆ’2/x=3\lim_{x\to\infty}\frac{3x}{x-2} = \lim_{x\to\infty}\frac{3}{1-2/x} = 3.

Answer

Vertical asymptote: x=2x = 2; Horizontal asymptote: y=3y = 3
Vertical asymptotes arise where the denominator is zero (and numerator is not). Horizontal asymptotes describe end behavior; when degrees are equal, the asymptote equals the ratio of leading coefficients.

About Asymptote

An asymptote is a line that a curve approaches arbitrarily closely as the input (or output) grows without bound, but typically never reaches.

Learn more about Asymptote โ†’

More Asymptote Examples