{"id":10492,"date":"2017-06-30t12:58:42","date_gmt":"2017-06-30t19:58:42","guid":{"rendered":"\/\/www.catharsisit.com\/hs\/?p=10492"},"modified":"2017-06-27t13:01:23","modified_gmt":"2017-06-27t20:01:23","slug":"ap-calculus-bc-review-riemann-sums","status":"publish","type":"post","link":"\/\/www.catharsisit.com\/hs\/ap\/ap-calculus-bc-review-riemann-sums\/","title":{"rendered":"ap calculus bc review: riemann sums"},"content":{"rendered":"
what are riemann sums? a riemann sum<\/strong> is a sum that estimates the value of a definite integral<\/em> (or area under a curve<\/em> if the function is positive). there are a number of different types of riemann sum that are important to master for the ap calculus bc exam.<\/p>\n we’ll cover the basics and see a few examples below.<\/p>\n given a function f<\/em>(x<\/em>), and an interval [a<\/em>, b<\/em>], a riemann sum<\/strong> estimates the value of the definite integral of f<\/em>(x<\/em>) from x<\/em> = a<\/em> to x<\/em> = b<\/em> according to the formula:<\/p>\n <\/p>\n first of all, it’s important to know what all that notation means.<\/p>\n that big greek letter sigma<\/em> (σ) is an instruction to add up a bunch of terms.<\/p>\n <\/p>\n what follows the σ are the terms that you will compute and add up. <\/p>\n each term is an area calculation for a rectangle. as you know, the area of any rectangle is equal to its height times its width. <\/p>\n in the case of a riemann sum, the heights are always function values:<\/p>\n <\/p>\n on the other hand, the width is the same for each rectangle, and there’s a formula to find it:<\/p>\n <\/p>\n here, a<\/em> and b<\/em> are the given endpoints of the interval. (equivalently, those are the bounds of integration in a definite integral.) the variable n<\/em> stands for the number of rectangles in the riemann sum.<\/p>\n we will also need to know about the points xk<\/sub><\/em> that serve to cut up the interval. here’s a formula to find each one (just plugin in k<\/em> = 0, 1, 2, …, n<\/em>).<\/p>\n <\/p>\n now different kinds of riemann sums use these xk<\/sub><\/em> points in different ways. although it seems like a lot to remember, the process is actually pretty straightforward. try not to stress out!<\/p>\nriemann sums — definition<\/h2>\n
what does it all mean???<\/h3>\n