00:01
So this question is asking us to graph the function over the given interval, partition the interval into four subintervals of equal length, and then add to our sketch the rectangles associated to even some of those for the left -hand endpoint, right -hand endpoint, and midpoints.
00:17
So first off, we want to graph this function on this interval.
00:24
So we have sign of x plus 1.
00:26
I already know that the graph of sign of x is going to look like this.
00:38
So where you have negative 1 and 1 is the heights of these.
00:44
Here it's going to be negative pi to pi.
00:49
So we have that sign of x.
00:51
All we're going to do is lift this entire thing up 1 in order to graph this.
01:00
So that's going to make my graph look like negative pi pie.
01:12
There i go.
01:19
And i meet this point here, my one, two here.
01:25
I cross at the one now instead of zero, come up and meet the two, and i'm only going to pie, so i'm going to just have that.
01:37
So it looks just like this, we're just raising it up one.
01:42
And so the problem also said that we are partitioning this into four sub -intervals.
01:47
So to find my delta x here, i'm just going to take my endpoints, subtract them, divided by two.
02:01
So pi minus negative pi is 2 pi divided by 4 so it's just going to be pi over 2.
02:10
So that's going to fill in what these are.
02:16
So the first problem will ask us to find the left hand endpoint.
02:19
So i'm going to start at my very left endpoint here and make my rectangle.
02:25
I'm going to come up until i hit the function.
02:30
And then i'm going to go across the length of my delta x.
02:37
So that's my first rectangle.
02:39
For the next one, i want to start here.
02:42
I don't go up any.
02:43
It's just zero right here.
02:45
This graph hits it there.
02:47
So i and just go across until i hit my next point.
02:56
So here i go up until i hit the function.
03:01
Once hit the function, i go cross to my next point.
03:10
So there's another rectangle.
03:11
And then i do the same thing here.
03:13
So i go up.
03:14
I hit my function.
03:15
Go crossed to pie.
03:21
And that's my last rectangle...