R

From open-encyclopedia.com - the free encyclopedia.

Latin alphabet
	Aa	Bb	Cc	Dd
Ee	Ff	Gg	Hh	Ii	Jj
Kk	Ll	Mm	Nn	Oo	Pp
Qq	Rr	Ss	Tt	Uu	Vv
	Ww	Xx	Yy	Zz

R r

R is the eighteenth letter of the Latin alphabet.

Semitic Rêš (the head) developed into Greek Ρω (Rô). The sound value /r/ however was maintained in Greek as well as Etruscan and Latin. The finishing stroke was added to the Greek Rho to distinguish it from a later form of the Greek Pi, at a time when there were only capital letters in Latin. It is usually one of the liquid consonants, though there are many ways it is pronounced in European languages.

In typography, there was once a form called the half r, which was lost before the long s was.

Romeo represents the letter R in the NATO phonetic alphabet.

Meanings for R

In biochemistry, R is the symbol for arginine.
In calendars, R is often used as an abbreviation for Thursday instead of T, to avoid confusion with Tuesday.
In chemistry,
- R denotes the molar gas constant.
- In organic chemistry, R is the symbol for the hydrocarbon chain.
In chess, R is a notation symbol for the rook piece.
In the RGB color model, R stands for the color red.
In commerce, R with an enclosing circle, ®, denotes a registered trademark.
In computing, R is the name of a statistical programming language based on S; see R programming language
In driving a motor vehicle, R designates the reverse gear of a transmission.
In electrical engineering, R is often the variable for electrical resistance
In film, R is a rating given for films given by film classification boards (such as the Motion Picture Association of America in the US); see R (rating)
- R is a character in the James Bond film The World Is Not Enough.
In financial securities, R is the stock symbol for Ryder Systems Inc.
In geometry, r is often a variable for the radius of a circle
In law, R. stands for Rex (king) or Regina (queen) in court citations in countries that recognize the British monarch as head of state.
In mathematics, blackboard bold <math>\mathbb{R}<math> represents the real numbers
In navigation, R denotes the relative direction "right"; see left and right.
In physics, R is the symbol for roentgen, a unit of dosage of X-rays or gamma radiation.
In radiocommunication, R is one of the ITU prefixes allocated to Russia.
In the romanization of the Japanese language, the letter R was selected instead of the letter L for the syllables in the tenth tier of the kana, for both the Hepburn system and the Kunrei, amongst others.
In statistics,
- R is the name of a statistical programming language based on S; see R programming language
- r is the Pearson product-moment correlation coefficient

R

Meanings for R

See also