00:01
In this problem, we want to find the domain on which f is 1 to 1 and a formula for the inverse of f restricted to this domain.
00:10
And then it wants us to sketch the graphs of f and the inverse.
00:13
So let's just go ahead first and sketch f of x because if we want to know whether or not it's 1 to 1, we can use the horizontal line test to figure that out.
00:21
So the graph of 1 over x plus 1 is looking something like this.
00:28
It's kind of hard to sketch, but this is what it should roughly.
00:31
Look like.
00:32
It can also plug it into your graphic and calculator to see.
00:34
It looks like that and it does indeed pass the horizontal line test.
00:39
So we can say yes, we're good to go.
00:41
It's one to one.
00:43
So now let's figure out what the domain is and we can say that the domain is all real numbers except for when x equals negative one.
00:52
So x cannot equal negative one.
00:53
Because if we have x equals negative one and we plug it into f of x, we get one over zero, which is impossible to get.
01:00
So our domain is all real numbers except for when x is negative 1.
01:05
So now let's find our inverse...