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Okay, welcome back, numerate.
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Here we go.
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All right, we're in chapter 5, section 1 of thomas's calculus 14th edition.
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We're on page 258, number 19.
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Now, we're not given a function or a graph this time to estimate an area.
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We're given a table of values.
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F of 0 is 50, f of 1 is 70.
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It increases all the way to f of 8 at 720.
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So it's an increasing function.
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So a right remand sum would be an underestimate, and a lfrea sum would be an underestimate.
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They're asking us to give us to give us.
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Overnumbered under estimates for five hours worth.
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Let's see, what is this? this table is given is time in hours and the function value is leakage of oil tanker leaking oil in gallons per hour.
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Okay, so i'm gonna say that the total amount of oil lost is, now let's make this easy.
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They want five rectangles.
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They want from the first five hours, right? so i'm going to say delta x of 1, and then f of 1, which is 70, plus f of 2, which is 97, plus f of 3, which is 136, plus f of 4, which is 190.
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This will be my underestimate.
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And f of 5 was 265.
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And i punch this up in my calculator already.
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I got 758 gallons of oil.
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Leaked in the first five hours of the leak.
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All right, because delta x is in hours and the y values are in gallons per hour, so the units we're getting here are gallons.
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All right, what's my overestimate? that would be my left sum, which is going to be delta x is 1 times f of 0, which is 50, so we're just shifting to the left, plus f of 1, plus f of 2, plus f of 3, plus f of my right side, yeah, my right sum is an omens.
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This is my underestimate.
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Okay.
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And f of 4, which is 190.
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So we're using a lot of the same numbers.
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So we're dropping the $256 and adding the 50s.
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So we're using f of 0 and not f of 5.
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Here we're using f of 1 to f of 5.
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This is f of 0 to f of 4.
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And that sum i got, let's see what i put it.
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I got 543 gallons...