How do you evaluate the limit #lim_(x to -1) (3x)/(x^2+2x+1)#?

1 Answer
Joe K.
Oct 24, 2017

The limit does not exist

Explanation:

The first method that should always be checked when calculating a limit is substitution. In this case, we substitute the value -1 into the expression. That yields #(-3)/0# and this value is undefined. When a value of a limit is undefined, a limit at that point does not exist.

I would like to point out that an undefined value is different from an indeterminate form. There are many indeterminate form, and the most common indeterminate form that does not include infinity is #0/0#. However, if there is some value over zero, this is different, like in the solution to this specific limit. Any value over zero is undefined and that results in a non-existent limit.

Related questions
See all questions in Determining Limits Algebraically
Impact of this question
4348 views around the world
You can reuse this answer
Creative Commons License