January 2012 - Page 2 of 9 - Math and Multimedia

Complex Numbers and their Properties

January 28, 2012 GB High School Mathematics

Imaginary numbers as we have discussed in Tuesday’s post are numbers of the form bi where $b$ is a real number and $i = \sqrt{-1}$ . The term imaginary as (opposed to real) was first used by Rene Descartes, the mathematician who invented Coordinate Geometry — the Cartesian plane in particular. Leonhard Euler was the one who introduced the symbol $i$ for $\sqrt{-1}$ .

Leonhard Euler

Gerolamo Cardano, a pioneer in probability, was the one who suggested the use of numbers of the form $a + bi$ where $a$ and $b$ are real numbers and $i = \sqrt{-1}$ . Numbers of this form were named complex numbers by Carl Frederich Gauss.The real part of $a + bi$ is $a$ and the imaginary part is bi. » Read more

One comment carl frederich gauss, complex numbers, imaginary numbers, leonhard euler

New header, Carnival 20, and more

January 27, 2012 GB Announcements, Miscellaneous

A blessed morning to everyone. I have not created a math or multimedia post for today, but here are a few announcements:

Math and Multimedia has a new header image. I created it using Banner Fans, a very handy online tool for creating banners. The background image was taken from Anssi Koskinen‘s photo collection on Flickr. I chose the abacus as header because it shows the connection between mathematics and the tools used in teaching.
The Math and Multimedia Carnival 20 will be hosted by GeoGebra Applet Central. Deadline of submissions is February 18 and post date is February 20. Click here to submit your entries or email me directly.
The Math and Multimedia Carnival is accepting hosts. The earliest available schedule is March 2012. Please email me if you’re interested.
I wrote several series that I have not finished yet: Divisibility Rules, OpenOffice Tutorial, and Geometer’s Sketchpad Essentials. I have not totally forgotten them; I am planning to finish them this first quarter.
All tutorials in the GeoGebra Essentials Series have been updated to GeoGebra 4.0. I have also updated the first six tutorials in the GeoGebra Intermediate Tutorial Series.
If you like Math and Multimedia, just click the +1 button above or subscribe and share.

That’s all for today. Happy weekend!

Leave a comment GeoGebra Tutorials, math and multimedia

Organize your RSS Feeds with Feedly

January 26, 2012 GB Web 2.0 Technology

If you read a lot of sites and blogs, and you subscribe to RSS feeds, you may want to organize your feeds with Feedly. It is a website that creates a magazine-like start page for all RSS feeds. It allows users to import feeds from Google Reader and categorize them.

Feedly is available as an Android app, iPad app, and Google Chrome web app. It is also available as a Safari and Firefox extensions. In addition, Feedly can be integrated with Twitter, Facebook, and Tumblr.

Leave a comment feed reader, feedly, Google reader, magazline-like feed reader, RSS Feeds

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