lim as x->+1

x^3 -1/x^2 -1

lim as x->-1

x^3 -1/x^2 -1

lim as x->1

x^3 -1/x^2 -1

x^3 - 1 = (x-1)(x^2 + x + 1)

x^2 - 1 = (x-1)(x+1)
as x->1, you get (1+1+1)/(1+1) = 3/2

As x -> -1 you get 1/0, + or - depending on the direction.