Question about rational functions and horizontal asymptotes
I am working on a math problem for class and am stumped by the nature of its horizontal asymptote.
The equation is f(x) = x / (x+5)(x-2).
Based on the rules for horizontal asymptotes given to me in class, when the degree of the leading coefficient for the denominator is larger than the degree of the leading coefficient for the numerator, the horizontal asymptote is always Y = 0. Since the numerator is X and the denominator is X^2, the denominator is larger so Y = 0.
For the equation above, the horizontal asymptote holds true as X goes towards positive and negative infinity outside of the vertical asymptotes (X = -5 & X = 2). However, inbetween the two vertical asymptotes, the graph crosses the X axis at (0,0).
I am curious why the function behaves this way, and if there is any vocabulary for this phenomenon.