Add new comment | plus.maths.org

Permalink Submitted by Angela Richardson on December 27, 2011

Should it be R=a(1-e^2)/(1-ecos(theta))?
Otherwise, great article.

Maths in a minute

Want facts and want them fast? Our Maths in a minute series explores key mathematical concepts in just a few words.

The maths of randomness

Randomness is surprisingly hard to define. Fortunately the mathematical language we use to describe it is beautifully well defined.
The unreasonable relationship between mathematics and physics

Can physics do for maths what maths has done for physics?
Exploring rare genetic resources

You could help researchers understand the genetics, and potential links, between mathematical talent and autism.
The two envelopes problem solved

Here's a resolution for one of probability theory's most famous paradoxes.
Arithmetic billiards

Need to find the least common multiple or greatest common divisor of two numbers? A billiard table of the right proportions holds the answers!