00:01
Okay, let's explain why the function f of x equals 1 over x plus 2 is discontinuous at a equals negative 2.
00:07
So let's talk about limits.
00:11
The limit as x approaches 2 from the left of 1 over x plus 2.
00:20
This number is going to be something like a little bit less than 2, right? so like 1 .999999 .99 .99 .99.
00:29
It helps to think of it that way.
00:34
Sorry, this is negative too.
00:35
So this should be negative 1 .9999.
00:41
Negative 1 .999 .9999.
00:43
So if we plug that in, we get the limit.
00:48
Okay.
00:48
We already plugged it in so we don't need the limit sign.
00:51
We get one over.
00:53
And this is sort of theoretical.
00:55
So you don't really want to show this work if you can avoid it.
00:58
But negative, 1 .1 .1.
00:59
1 .99999 .9 .9 .9.
01:01
Plus 2 is going to be something 0 -000 -1.
01:05
1 over an extremely small number leads us to infinity...