00:01
I hope s and t don't take too much thought, because what i actually did is i took the equation i gave you for the velocity and i typed into y1 into my calculator, and i think you could tell just by looking at the problem that we're going from 0 to 2 with n equals 4 rectangles, so that the width, and they even give it to you in the directions, that the width of each rectangle is 0 .5.
00:30
But if you need to see the work as to why, it's the upper bound minus the lower bound divided by the number of rectangles, which is 1 half.
00:38
So now what you need to do is multiply that number by f of 0, and then you add to it, let me just do this one at a time, because sometimes it takes a while for students to realize that you could just factor out that 0 .5, f of 1, and then add to it 0 .5 times f of 1 .5.
01:12
There we go.
01:13
So yeah, let me just go ahead and point out that you could have factored that out, that might help you out.
01:22
5, f of 1, and then f of 1 .5.
01:28
So let me just stick with that real quick.
01:30
And like i said, i typed it into the calculator, but they told you a few of the values, like i'm reading the directions, and i say b of 1, that's why i should have written b instead of f, maybe i'll do that in the next one, that b of 1 equals 2, and you're multiplying by that 0 .5.
01:49
I'm just doing this all at once, b of 0 plus b of 0 .5 plus b of 1 plus b of 1 .5.
02:05
And i got an answer on this to be 2 .9375.
02:13
And i'm not sure where you're supposed to round to, so let me circle that and just move on.
02:21
As a fraction though, it is 47 sixteenths if that's counted wrong.
02:27
So the only thing that's different for t is that it's a 0 .5, let me go back to b, but you're doing the upper values.
02:35
So you're starting at 0 .5, b of 1, and then b of 1 .5.
02:41
See how i'm doing the rectangles, the heights on the right side? and that's why i'm including 2 and not including 0 from up here...