f(x) = ABS(x^2 - 1)/((x - 1)·(x + 2))
für -1 < x < 1 --> f(x) = (1 - x^2)/((x - 1)·(x + 2)) = 1/(x + 2) - 1
für x < -1 oder x > 1 --> f(x) = (x^2 - 1)/((x - 1)·(x + 2)) = 1 - 1/(x + 2)
D = R \ {-2 ; 1}
lim (x --> -∞) f(x) = 1 - 1/(x + 2) = 1
lim (x --> ∞) f(x) = 1 - 1/(x + 2) = 1
lim (x --> -2) f(x) = 1 - 1/(x + 2) = -∞
lim (x --> 1-) f(x) = 1/(x + 2) - 1 = 1/3 - 1 = -2/3
lim (x --> 1+) f(x) = 1 - 1/(x + 2) = 1 - 1/3 = 2/3
lim (x --> -1-) f(x) = 1 - 1/(x + 2) = 1 - 1 = 0
lim (x --> -1+) f(x) = 1/(x + 2) - 1 = 1 - 1 = 0