Channel: Krista King

Category: Education

Tags: educationalarea estimationdefinite integralconvertingkrista kingestimating areaconvertcalculusarea approximationconvert to a definite integralconvert riemann sumsriemann sumsintegralapproximating area

Description: 0:25 // Definition of the Riemann sum 0:50 // What you need in order to use a Riemann sum to find area 1:09 // The difference between a Riemann sum and an integral 1:34 // Converting a Riemann sum into a definite integral 2:09 // Converting an example Riemann sum into a definite integral 2:35 // Summarizing how to use the Riemann sum versus the definite integral We know that Riemann sums estimate area, and we know that integrals find exact area. But how do we convert a Riemann sum into a definite integral? The simple answer is that we just use an infinite number of rectangles to find the area, instead of a finite number of rectangles, like we normally would when we're using a Riemann sum. If we want to express the fact that we're going to use an infinite number of rectangles, we need to add a limit out in front of the integral as n (the number of rectangles) approaches infinity, and then the Riemann sum has become a definite integral. As long as we know the interval over which we're trying to find area, we can change the limit and summation notation into integral notation, with the limits of integration reflecting the interval we're interested in. We change the function f(x_i) into a function f(x), and we change the delta x into dx. And that's actually all it takes to change the Riemann sum into a definite integral. Music by Joakim Karud: soundcloud.com/joakimkarud ● ● ● GET EXTRA HELP ● ● ● If you could use some extra help with your math class, then check out Krista’s website // kristakingmath.com ● ● ● CONNECT WITH KRISTA ● ● ● Hi, I’m Krista! I make math courses to keep you from banging your head against the wall. ;) Math class was always so frustrating for me. I’d go to a class, spend hours on homework, and three days later have an “Ah-ha!” moment about how the problems worked that could have slashed my homework time in half. I’d think, “WHY didn’t my teacher just tell me this in the first place?!” So I started tutoring to keep other people out of the same aggravating, time-sucking cycle. Since then, I’ve recorded tons of videos and written out cheat-sheet style notes and formula sheets to help every math student—from basic middle school classes to advanced college calculus—figure out what’s going on, understand the important concepts, and pass their classes, once and for all. Interested in getting help? Learn more here: kristakingmath.com FACEBOOK // facebook.com/KristaKingMath TWITTER // twitter.com/KristaKingMath INSTAGRAM // instagram.com/kristakingmath PINTEREST // pinterest.com/KristaKingMath GOOGLE+ // plus.google.com/+Integralcalc QUORA // quora.com/profile/Krista-King