Precalculus

Lecture 12: Rational Functions

In this video, we look at rational functions. Rational functions are obtained by taking the ratio of two polynomial functions. The word "rational" has "ratio" in it for that very reason.

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Bonus Video: Rational Functions and Slant Asymptotes

If a rational function has a numerator that is exactly one degree larger than the degree of the denominator, then it has what is called a "slant" asymptote. Asymptotic behavior of a function is "what the function looks like" when we go far out to the right or left. In the case when the numerator is one degree larger than the denominator, the graph starts looking like a straight line when you go far out to the left or right. Whatever that straight line is, that is the slant asymptote. That's what we talk about in this video.