Online Test Banks
Score higher
See Online Test Banks
Learning anything is easy
Browse Online Courses
Mobile Apps
Learning on the go
Explore Mobile Apps
Dummies Store
Shop for books and more
Start Shopping

How to Write Riemann Sums with Sigma Notation

You can use sigma notation to write out the right-rectangle sum for a function. For example, say you’ve got f (x) = x2 + 1.

By the way, you don’t need sigma notation for the math that follows. It’s just a “convenience” — yeah, right. Cross your fingers and hope that your teacher decides not to cover the following. It can get pretty hairy.

Recall the formula for a right sum:


Here’s the same formula written with sigma notation:


Now, work this formula out for the six right rectangles in the figure below.


In the figure, six right rectangles approximate the area under


between 0 and 3.


If you plug 1 into i, then 2, then 3, and so on up to 6 and do the math, you get the sum of the areas of the rectangles in the above figure. This sigma notation is just a fancy way of writing the sum of the areas of the six rectangles.

  • Add a Comment
  • Print
  • Share
blog comments powered by Disqus

Inside Sweepstakes

Win $500. Easy.