# Category Archives: Mathematics

## Standard Deviation in IDL

The built in IDL standard deviation function in IDL, STDDEV, uses the moment function which treats the standard deviation as a sample, rather than a population. A short programme can give us both options.

## Standard Deviation of Noise in TV Viewing Figures

As discussed in my last post we found that ‘the standard deviation of the noise in viewers is about 20% of the range of viewers’ for Grey’s Anatomy. I wanted to see if a similar figure was true for other … Continue reading

## Graphical Analysis of Grey’s Anatomy Viewing Figures

I recently started watching Grey’s Anatomy which I’ve been enjoying. However a friend of mine told me that the later episodes are not as good. So I thought I would have a look if the viewing figures reflected this. … Continue reading

## Velocity Required for Loop the Loop

Chris (@chris2306) got asked how fast you would need to be going to complete a loop the loop. This is what we got.

## Largest Known Prime Number

We have a new largest known prime number! So here is an obligatory post about prime numbers.

## It’s Snowing Outside!

I’m sitting in my office, at home, watching the snow falling outside and it got me thinking….

## The Crawshaw Method (for Quadratics)

Something all GCSE maths students (and above) need to know, and something that a large number of people use everyday, is how to factorize quadratic equations. However I’m amazed how few people know a decent (and easy) way of doing this!

## 1 = 2

Many people have seen “proofs” that 1 = 2. However most of them have an obvious fallacy – a division by 0.

## Sine Rule on a Sphere

A couple of days ago I wrote a post on what, and how to find, the cosine rule on a sphere. In this post I’ll show you the sine rule on a sphere.

## Cosine Rule on a Sphere

As all (well, at least those that can remember) 15+ year old’s know, to find the length of a side of a non-right angled triangle you can’t use Pythagoras theorem and instead require the so called ‘Cosine Rule’.