Graphical Animation to Demonstrate the Spawning of
Asymptotes from a Missing Point on the Graph of a Rational Function
Jason Laska
The rational function f(x)=(x2+4x-5)/(x-1) = [(x+5)(x-1)]/(x-1) = x+5, when x¹1
has a removable discontinuity at (1,6). By adding a single controlled parameter "A" to the equation one can use this rational
function f(x)=(x2+4Ax-5)/(x-1) to simulate the spawning of
asymptotes from the removable discontinuity. In the following
example the parameter is being decreased resulting in the following
asymptotes:

When the parameter increases it can be seen that the function spawns
asymptotes in the opposite direction
of the previous animation.

It can therefore be deduced that, in this instance of rational functions, the spawning of asymptotes is directly related
to the coefficient of the middle term.