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See also Asymptotic analysis
An asymptote to a curve is a straight line that the curve approaches in such a manner that it becomes as close as one might wish to the line by going far
enough along the line. A "real-life" example of such an asymptotic relationship would involve a kitten standing 1m from a box; and, if every hour the kitten walks halfway to the box; this results in a situation in
which the kitten never reaches the box; because, the distance it travels, during
each hour, is never more than halfway to the box. (Compare Zeno's
paradoxes.)
A specific example of asymptotes can be found in the graph
of the function f(x) = 1 / x,
in which two asymptotes are being approached: the line y = 0 and the line x = 0. The curve approaches them,
but, never reaches them. A curve approaching a vertical asymptote (such as in the
preceding example's y = 0, which has an undefined slope) could be said to approach an "infinite limit", although infinity is not technically considered a
limit. A curve approaching a horizontal asymptote (such as in the preceding
example's x = 0, which has a slope of 0) does approach a "true limit".
Asymptotes do not need to be parallel to the x- and y-axes, as shown by the graph of x + x-1,
which is asymptotic to both the y-axis and the line y = x. When an asymptote is not parallel to
the x or y axes, it is called an oblique asymptote.
A function f(x) can be said to be asymptotic to a function g(x) as
x→∞. This has any of four distinct meanings:
- f(x) - g(x) → 0.
- f(x) / g(x) → 1.
- f(x) / g(x) has a nonzero limit.
- f(x) / g(x) is bounded and does not approach zero. See Big O notation.
Horizontal Asymptotes Locator Theorem
Ask: What is the highest power of x in the numerator (N)?
What is the highest power of x in the denominator
(D)?
- If N = D, then you have the asymptote at Y=Leading Coefficient of
Numerator/Leading Coefficient of Denominator
- If N > D Then there is no strictly Horizontal Asymptote
- If N < D Then the X-Axis is your Asymptote.
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