An asymptote of the curve y = f(x) is a straight line such that the distance between the curve and the straight line lends to zero when the points on the curve approach infinity.
Since Signum is a linear function, it is itself its asymptote
Linear function is, by definition, the graph of a line, and asymptotes are lines that show the end behavior of the function. So we can say that a linear function is its own asymptote.