Similarly, if the exponent is equal to 3, then the power is called cube, because the volume of a cube is calculated using formula_23. So
If the exponent is equal to -1, then the power is simply the reciprocal of the base. So
If the exponent is an integer less than 0, then the power is the reciprocal raised to the opposite exponent. For example:
If the exponent is equal to formula_28, then the result of exponentiation is the square root of the base, with formula_29 For example:
Similarly, if the exponent is formula_31, then the result is the nth root, where:
If the exponent is a rational number formula_33, then the result is the "q"th root of the base raised to the power of "p":
In some cases, the exponent may not even be rational. To raise a base "a" to an irrational "x"th power, we use an infinite sequence of rational numbers ("x"), whose limit is x:
like this:
There are some rules which make the calculation of exponents easier:
It is possible to calculate exponentiation of matrices. In this case, the matrix must be square. For example, formula_44.
Both addition and multiplication are commutative. For example, 2+3 is the same as 3+2, and 2 · 3 is the same as 3 · 2. Although exponentiation is repeated multiplication, it is not commutative. For example, 2³=8, but 3²=9.
Addition has one inverse operation: subtraction. Also, multiplication has one inverse operation: division.
But exponentiation has two inverse operations: The root and the logarithm. This is the case because the exponentiation is not commutative. You can see this in this example:
Sega
The Sega Mega Drive (, "Mega Doraibu") was a 16-bit video game console made by Sega. It was in market in Japan in (1988), and in Europe and the rest of the world in (1990). In North America, it was called "Sega Genesis".
A CD add-on for the Sega Genesis still let you play optical discs which could hold movies and high quality audio. It was not well received but has a strong base of fans.
The Sega 32X was an attempt to top the graphics of the Super Nintendo in the 90's. Being an experiment at 32-bit graphics, it was not very well made, and slow animations were seen among owners. The 32X later died, but Sega didn't stop there. Later, they made CD32X games, which required both the 32X and CD.
Sega Saturn was released on November 22/10, 1997/1999 in Japan/France. It was the first Sega video game console with 3D graphics. Sega released two versions of the Saturn : the first generation was black and with small controllers, and the second was white. One of its most popular games was Sonic R.
Sega Dreamcast (; originally called "Dural," and "Katana") is the last machine made by Sega that can play video games. It was sold before the PlayStation 2, GameCube, or Xbox came out. However, not many people bought it after the PlayStation 2 was released, so in the end Sega decided to stop making them.
Notes
Primary school
A primary school (or elementary school) is a school for children between the ages of about five and eleven. It comes after preschool. When children finish learning at primary school, they go to secondary school.
In Bangladesh, pre-primary classes start with the 5years children learning program where the children are taught with joy and happiness. Students from ages six to eleven, they finish learning from primary school and prepared for secondary.
In the United Kingdom, a primary school usually comprises a nursery and the first seven years of a child's full-time learning. In Australia and the United States, primary school begins with kindergarten. It lasts for six years, usually until the fifth or sixth grade. In the U.S., "elementary school" is a more common term for public primary schools. "Primary school" is often used in private or independent schools. (In private or independent schools the government does not give the schools money.)
In India, "Primary Education" means the 'Nursery', the 'Kindergarten' and four years of regular schooling thereafter. Admission to Nursery classes is for children above two years so that the age is 6+ when entering Class I. Children are taught language (mother tongue and English) reading/writing skills, basic arithmetic and quite a good amount of general information about the country, people, statesmen, great people, flora & animals. However, this is true only for schools in the urban areas. Rural schools do not have Nursery or Kindergarten; they admit straight at Class I when the child is six. Further, the rural schools use the mother tongue as medium of instruction, not resorting to English in any way. Primary education is free in government schools. Moreover, rural primary schools offer free mid-day meals to children (the government pays for it) so that the drop out rate comes down. States of West Bengal, Maharashtra, Manipur, Nagaland and Kerala have done very good work in this way of spreading primary education.
In Singapore, primary school refers to those students who are normally between the ages of 7 to 12. Primary School is classified as P1 to P6 for Primary 1 to Primary 6 respectively. At the end of P6, students sit for a national level Primary School Leaving Exam (PSLE) which is used for placement into Secondary School. Prior to Primary School, pupils attend Kindergarten School for 2 years.
In Germany, the primary school is called "Grundschule" and is normally from first grade to fourth grade so it is usually for children who are between six and ten years old. In some eastern states, for example in Berlin, the Primary School is for children up to age 12. In most German states the children start learning English in third grade on a very low level, they learn how to count and the names of the colors and other easy things. But because of that low level a German child who has finished Primary School is normally not able to form correct English sentences. In Primary School the children are prepared for the secondary education. Primary School students attend three main subjects: Math, German and General Knowledge ("Sachkunde"). In General Knowledge the children learn about nature, about their own body, how to ride a bicycle safely and something about the city they live in and of course about Germany. Beside those main subjects the children attend subjects like arts, music and Physical Education.
Restaurant
A restaurant (sometimes known as a diner) is a place where cooked food is sold to the public, and where people sit down to eat it. It is also a place where people go to enjoy the time and to eat a meal.
Some restaurants are a chain, meaning that there are restaurants which have the same name and serve the same food. McDonald's, Burger King, and Pizza Hut are examples of chain restaurants that are all over the world. These restaurants serve fast food, that is, inexpensive food, prepared and served quickly. At some, you do not have to even get out of the car to eat. You can pay and get your order from a window. These places are called drive-throughs.
There are also chain restaurants that serve slightly more expensive food. They are called fast casual restaurants. Applebee's and Perkins are examples of this type of chain restaurant.
Haute cuisine or 'fine dining' is found in a guide, such as the "Michelin Guide", the most famous restaurant guide in the world. Their 3-star rosettes are given only to restaurants with the highest standards of cooking and service. Interestingly, the Guide gives more 3-stars to Tokyo and Kyoto than to Paris, London and New York together. Traditionally, the restaurants of top hotels such as the Hotel de Paris in Monte Carlo or the Hôtel Ritz Paris were the main places recognized for fine dining. Today, most Michelin Guide restaurants are separate establishments.
In Ancient Greece and Rome there were small restaurant-bars offering food and drinks. They were called "thermopolia" (singular "thermopolium"). Many dwellings did not have kitchens, and eating out was an important part of socializing.