How do you find the limit of #((h-1)^2+1)/h# as h approaches 0?

2 Answers
May 20, 2017

#lim_(h->0) ((h-1)^2+1)/h = oo#

Explanation:

Plugging in #0# for #h# gives that:

#lim_(h->0) ((h-1)^2+1)/h = ((0-1)^2+1)/0=2/0#

Since #2/0# equates to the indeterminate form #oo#, we can say that #lim_(h->0) ((h-1)^2+1)/h = oo#.

May 20, 2017

The limit is divergent.

Explanation:

The whole point of evaluating a limit is that we do not generally look (or care) at the behaviour when #h=0#, just when #h rarr 0#

In this case we have:

# lim_(h rarr 0) ((h-1)^2+1)/h = lim_(h rarr 0) ((h^2-2h+1)+1)/h #
# " " = lim_(h rarr 0) (h^2-2h+2)/h #
# " " = lim_(h rarr 0) (h-2+2/h) #
# " " = lim_(h rarr 0) h - lim_(h rarr 0)2+2lim_(h rarr 0)1/h #

The First limit exists:

# lim_(h rarr 0) h = 0#

The Second limit exists

# lim_(h rarr 0)2 = 2 #

However the third limit diverges

# 2lim_(h rarr 0)1/h rarr oo#

As #1/h#increases without bound as #h rarr 0#

Hence the initial limit is divergent.