00:01
For this problem, we are asked to consider the area under the graph of y equals 4x from 0 to 5, where part a is to sketch the graph in the corresponding area.
00:09
So that's our graph, and that is the corresponding area down beneath.
00:15
Then for part b, we're asked to partition the interval 0 to 5 into n - excuse me, n sub -intervals, each of equal length.
00:22
So, first, we want to figure out what our sub -interval width is going to be.
00:27
We know we're going from 0 to 5, so our total width is going to be 5.
00:32
And then we're splitting it up into n sub -intervals, so it's going to be 5 over n.
00:36
Then that means that when we're splitting up into those sub -intervals, we'd go from 0 to 5 over n, and then from 5 over n, oops, 5 over n up to 2 times 5 over n, and then we'd go to from 2 times 5 over n to 3 times 5 over n, and so on.
01:02
That's for b.
01:02
Now for part c, we're asked to show, that little s n equals the sum from i equals 1 up to n of i minus 1 times 100 over n squared.
01:13
Now one moment here.
01:16
So we know that each for our i -th rectangle, especially since we're going with the left -hand side, we're starting with i equals 1, we'd be evaluating at f of x i, and we'd be multiplying by delta x...