How do you find the asymptotes for f(x)= x/(x(x-2))?

1 Answer
Mar 28, 2016

Vertical asymptotes, horizontal asymptotes and "holes" can be found in this function.

Explanation:

First, cancel the factor of x from both the numerator and denominator of the expression:
f(x) = 1/(x-2)

That factor being removed, causes a "hole" in the graph. This is sometimes called a removable discontinuity. So, at x!=0, there is a "hole".

To find a vertical asymptote, set the denominator equal to 0 and solve:
x - 2 = 0 so x = 2 is the vertical asymptote.

To find a horizontal asymptote, notice that the degree of x in the denominator is higher than the degree of x in the numerator. That is, x^0 in the numerator and x^1 in the denominator. Therefore, large positive or negative values of x will cause the expression to approach 0. That means that a horizontal asymptote will be y = 0.

Still not sure about this? Substitute in large positive and negative values for x like 1000000 or -1000000...Your output values will be very, very small!