## complex number

Producing electricity securely, safely, reliably and cheaply has many challenges. Chris Budd explains that the answer to many of these issues is maths.

Here's a quick introduction to the beauty queen amongst mathematical formulas.

This year's Abel Prize has been awarded to the Belgian mathematician Pierre Deligne for "seminal contributions to algebraic geometry and for their transformative impact on number theory, representation theory, and related fields".

Solving equations often involves taking square roots of numbers and if you're not careful you might accidentally take a square root of something that's negative. That isn't allowed of course, but if you hold your breath and just carry on, then you might eventually square the illegal entity again and end up with a negative number that's a perfectly valid solution to your equation.

If you're bored with your holiday snaps, then why not turn them into fractals? A new result by US mathematicians shows that you can turn any reasonable 2D shape into a fractal, and the fractals involved are very special too. They are intimately related to the famous Mandelbrot set.

A new 3D version of the Mandelbrot set
Complex numbers — what are they, how do they work and what do they have to do with computer-generated movies, fractals and chaos? This teacher package brings together all Plus articles on complex numbers and gives some handy links to related problems on our sister site NRICH.
In the fourth and final part of our series celebrating 300 years since Leonhard Euler's birth, we let Euler speak for himself. Chris Sangwin takes us through excerpts of Euler's algebra text book and finds that modern teaching could have something to learn from Euler's methods.
Computer generated movies and electronic games: Joan Lasenby tells us about the mathematics and engineering behind them.
You've probably seen pictures of the famed Mandelbrot set and its mysterious cousins, the Julia sets. In this article Robert L. Devaney explores the maths behind these beauties and shows that they're loaded with mathematical meaning.