00:01
I hope i'm reading the problem correctly because the use of parentheses is kind of ambiguous.
00:06
I think it's supposed to be x, x minus one, but either way i can get you the process of doing the interval from four to seven with n equals six.
00:18
And so what i'm going to do is find the change in x in this problem, and what you want to do is the upper bound minus the lower bound, divided by the number of rectangles.
00:27
So we're looking at three divided by six, which is one half.
00:31
So what i would do is, if you wanted to just use your calculator, but what i'm really doing is i'm starting at four and then with intervals of one half, then i need to see what the value is at 4 .55.
00:46
Do you see how my intervals are going up by one half? six, 6 .5.
00:52
And i can stop right there because even though i could go to seven, i don't have to because the question asks you to do the lower riemann sum, the left riemann sum.
01:04
So what i would do is one half times f of 4 plus one half times f of 4 .5.
01:14
But see how i factored out the one half because it's the width of each one of these rectangles.
01:19
Five, f of 5 .5.
01:26
Let's move down here...