Recall that a *circle* in ^{2} is the set of points (*x*, *y*) that lie at a fixed distance, called the *radius*, from a fixed point, called the *centre* of the circle. We can use the techniques of coordinate geometry to find the equation of a circle with a given centre and radius.

3.1 Definition, properties and some applications

In the previous section we saw how to add two vectors and how to multiply a vector by a scalar, but we did not consider how to multiply two vectors. There are two different ways in which we can multiply two vectors, known as the *dot product* (or *scalar product*) and the *vector product*. They are given these names because the result of the first is a scalar and the result of the second is a vector. (We shall not consider vector products in this course.)

In the audio sec

2.4 Components and the arithmetic of vectors

We introduce now a different method of representing vectors, which will make the manipulation of vectors much easier. Thus we shall avoid having to solve problems involving vectors by drawing the vectors and making measurements, which is very time-consuming and never very accurate.

We can think of a vector as a translation, that is, as representing a movement by a certain amount in a given direction. Then we can use the Cartesian axes in the plane or in Author(s):

2.2 Multiplication by a scalar

In the collection of vectors sketched in Section 2.1, although **v** is not equal to **c**, the vectors **v** and **c** are closely related: **c** is a vector in the same direction as **v**, but it is twice as long as **v**. Thus it is natural to write 2**v** for **c**, since we can think of a journey repre

1.8 Intersection of two planes

We saw earlier that two arbitrary lines in ^{2} may intersect, be parallel, or coincide. In an analogous way, two arbitrary planes in

1.3 Parallel and perpendicular lines

We often wish to know whether two lines are *parallel* (that is, they never meet) or *perpendicular* (that is, they meet at right angles).

Two distinct lines, *y*Â =Â *m*_{1}*x* + *c*_{1} and *y*Â =Â *m*_{2}*x* + *c*_{2}, are parallel if and only if they have the same gradient; that is, if and only if *m*_{1}Â =Â *m*_{2}. For example, the lines *y*Â =Â âˆ’2*x* + 7 and

By the end of this unit you should be able to:

**Section 1**recognise the

*equation of a line*in the plane;determine the

*point of intersection*of two lines in the plane, if it exists;recognise the

*one-one correspondence*between the set of points in three-dimensional space and the set of ordered triples of real numbers;recognise the

*equation of a plane*in three dimensions.

The gathering, presentation and assessment of evidence are crucial and indeed inescapable parts of the practice of social science, hence the crucial role of evidence in the circuit of knowledge (see Figure 1).

The *ATM physical layer* is divided into two sub-layers: the transmission convergence sub-layer and the physical medium sub-layer.

Functions of the *transmission convergence sub-layer* include generating and receiving cells, and generating and verifying the cyclic redundancy check in the header error control field. For correct interpretation of ATM cells it is important to identify the beginning of a cell. In theory, if ATM cells are transmitted as a continuous stream of bits,

7.4 Elixirs of the nervous system: neurotrophins

According to Section 7.2 axons obtain an elixir from targets at their synapses.

Confirmation that there is indeed an elixir came from a series of events that reveals how much of science really works. Elmer Bucker, working with Hamburger in the mid-1940s, had removed a limb bud from a chick and replaced it with a tumour from

2.1 Zero electrical resistance

In this section we shall discuss some of the most important electrical properties of superconductors, with discussion of magnetic properties to follow in the next section.

The most obvious characteristic of a superconductor is the complete disappearance of its electrical resistance below a temperature that is known as its critical temperature. Experiments have been carried out to attempt to detect whether there is any small residual resistance in the superconducting state. A sensitive t

An interesting analysis of Napoleon's involvement in Spain is provided by Stendhal in *A Life of Napoleon*, chapters 36 to 43. Stendhal argues that Napoleon's basic error was to see Spain as susceptible to the imposition by the French of the kind of enlightened reforms which had been welcomed elsewhere in Europe. Stendhal particularises, in a way characteristic of Romantic writers, on what he considers a highly distinctive Spanish national character, which in his view explains the hostil

2008.08.22 - Special Young Benefactors Lecture

Our Young Benefactors membership organization held a special panel discussion on how to start, build, and care for a private art collection on 8/22/2008.

Another way to tackle unfamiliar words is to start a â€˜concept cardâ€™ system, using index cards. When you meet a word which seems important, take a new card and write the word at the top, followed by any useful information you have found. File the cards alphabetically and add details as you come across new information. (It is worth getting an index card box anyway, then you can try out various ways of using it to organise your studies.)

Drawn from Courtly India: The Conley Harris and Howard Truelove Collection

December 6, 2015 - March 27, 2016: This exhibition presents masterful drawings from the royal courts of northern India. Lovingly amassed by artist Conley Harris and architectural designer Howard Truelove, the collection features practice sketches, preparatory drawings, subtly modeled scenes, and lightly colored compositions created between the 1500s and 1800s. With images at different stages of completion, the collection allows for a fascinating look at Indian workshop practice. Alth

Student killed in clashes with police in Egypt

A student is reportedly killed in clashes between university student protesters and police in Cairo. Rough Cut (no reporter narration).
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Pratiques innovantes en enseignement - apprentissage, l'exemple d'Innovalangues (VidÃ©o)

Monica Masperi

MaÃ®tre de ConfÃ©rences (UniversitÃ© Grenoble Alpes)

Pratiques innovantes en enseignement - apprentissage, l'exemple d'Innovalangues

6 Phylogeny and cladistic analysis

In Section 3.3 the point was made that many physiologists consider that desert birds are successful because of their avian physiology, not because of any specific adaptations. While Williams and Tieleman's research on hoopoe larks demonstrated that desert species are capable of flexibility in metabolic rate and evaporative water loss, it suggested that adaptation is important too. The selective advantages of lowered BMR and TEWL for desert birds include reduced energy demand, and lower produc

Darwin Now Awards

Janice Ansine is a recipient of a Darwin Now Award. She is currently working on a variety of projects in Jamaica, looking at contemporary responses to Darwin and Into the historic role of Jamaica in providing material for his research.

The architecture of refugee protection

Annual Harrell-Bond Lecture 2012. Lecture by Professor Mariano-Florentino CuÃ©llar (Co-Director of the Stanford Center for International Security and Cooperation)recorded on 7 November 2012 at the Oxford Museum of Natural History.