Tag Archives: sigma

Sigma notation ninja tricks 2: splitting sums

Posted on March 18, 2017 by Brent

[Previous posts in this series: jumping constants] Trick 2: splitting sums I’ve written about this before, but it’s worth spelling it out for completeness’ sake. If you have a sum of something which is itself a sum, like this: you … Continue reading →

Posted in algebra, arithmetic | Tagged , , , , , | 3 Comments

Sigma notation ninja tricks 1: jumping constants

Posted on March 11, 2017 by Brent

Almost exactly ten years ago, I wrote a page on this blog explaining big-sigma notation. Since then it’s consistently been one of the highest-traffic posts on my blog, and still gets occasional comments and questions. A few days ago, a … Continue reading →

Posted in algebra, arithmetic | Tagged , , , , | 1 Comment

Sigmas and sums of squares

Posted on November 29, 2011 by Brent

Commenter Rachel recently asked, How would you find the sum of ? See here for an explanation of sigma notation—in this case it denotes the sum Of course, for any particular value of we can just plug in values and … Continue reading →

Posted in algebra | Tagged , , , , | 6 Comments