00:01
Hey guys, how's it going? in this problem, we're going to be graphing and finding the critical values of the function f of x equals 3 minus e to the negative x for all x values greater than are equal to 0.
00:11
So before i start graphing, let me quickly go ahead and make this asymptote here to kind of remind me not to go past this point.
00:22
I can sit on the line here, but i can't go past it.
00:28
So at x equals negative 1, you can plug that into your calculator.
00:32
I got 0 .28.
00:36
At x equals 0, i got the point y equals 2.
00:43
At x equals 1, i got 2 .63.
00:48
And at x equals 2, i got 2 .86.
00:53
So i'm going to just graph kind of a phantom point here to help me figure out how exactly the function is behaving.
01:01
So at x equals negative 1, we had something kind of like right here.
01:08
At x equals 0, we had y equals 2.
01:12
At 1, we had 2 .63, right about here.
01:19
And at 2, we had 2 .86.
01:24
So the graph kind of is going to go up like this.
01:35
And approach infinity.
01:39
But the slope, as you can see, is kind of slowing down here.
01:42
The change in y was about 0 .6.
01:47
The change of y between these two points was about 0 .2 something.
01:55
So this will tend off to positive infinity.
01:59
So next let's go ahead and take the first derivative find the critical values.
02:04
So this becomes 0 negative e to the negative x times by negative 1, e to the negative x.
02:14
To find the critical values, we set this equal to 0.
02:18
When does this function become zero? well, excuse me, sorry, i was moving something.
02:36
So when does this function become zero? well, we can set up another graph very quickly to test the values.
02:46
If x equals negative 1, we have 2 .71, about something like that.
02:52
Zero, we have 1.
02:54
One, we have e to the negative 1.
02:58
I got about 0 .37.
03:11
So overall, this function will behave something like this.
03:23
So we ask yourselves, when does this function cross the x -axis? well, it never does, but it will approach the x -axis as it approaches infinity.
03:39
So therefore, this function will never be equal to zero.
03:42
So there are no critical points...