Hello, I need some help with this:
Prove: lim x --> -1- 5/(x+1)^3 = neg. infinity
I am not sure how to do that.
a=-1
For a limit against neg. infinity I know that
if 0 < |x-a| < delta then f(x) < N
and for a left-hand limit I know
if a-delta < x < a then |f(x) - L| < epsilon
So I have
5/(x+1)^3 < N if |x+1| < delta
and
-1-delta < x < -1 if ???
I do not know how to combine them.
Thanks for any hints..