## Packages

One of the greatest advances in the biomedical sciences has been the unravelling of our genetic code. This new understanding sheds light on what makes organisms function and how they are related to each other, helps to combat diseases, and to convict criminals. But it also poses great mathematical challenges: the genetic revolution is an information explosion which can only be tamed using mathematical methods.

This teacher package brings together our material on trigonometry, from problems about simple triangles to the wavy behaviour of trig functions.

Maths is all about patterns and rhythms, so it's no surprise that there's plenty of maths in art. Whether it's the visual or the performing arts, maths can be a tool, an inspiration, or simply something that's naturally contained within the structures and patterns.

The year 2009 was International Year of Astronomy, and to celebrate, we asked you what you'd most like to know about your Universe in a series of online polls. You came up with seven questions, which we put to world-leading astronomers and cosmologists. Find their answers in seven articles, as well as some podcasts.

The notion of proof lies at the very heart of maths: it's when it comes to proving things that mathematicians let lose their genius and creativity, and in the process often discover unexpected surprises or deep philosophical issues. But proofs can also be daunting. So to help you and your students along, we've brought together a range of Plus articles on proofs.
This teacher package brings together all Plus articles on graph and network theory. Graphs and networks turn up in many real-life problems, from neuroscience to telecommunications. In the UK curriculum, they make a frequent appearance in the area known as decision maths. Our articles explore a wide range of related topics, from simple algorithms to complex network topologies.
In this issue's teacher package we look at some of the maths and science behind a recent expedition to the Arctic. The aim of the Catlin Arctic Survey was to gather data on ice thickness that will help to predict when the North Pole sea ice cover will melt, an event that will have dramatic consequence for the Arctic ecosystem and the Earth's climate as a whole. Plus was commissioned by Catlin Arctic Survey Education to produce mathematics and science enrichment material for ages 14 to 19 (key stages 4 and 5). The toolkits look at climate and sea ice models, GPS and cartography, how to predict future climate trends, and how to present statistical evidence.
From the geometry of Euclid to the shape of the Universe — geometry is a vast field. We've got plenty of articles exploring geometry from all angles, so have a look and take your pick.