How to open the root number, how to open the root number

Mouth calculation of the root number?

Memorize the root number of some commonly used numbers.

Needless to say, 1 under the root number is equal to 1

2 under the root number is approximately equal to.

3 under the root number is approximately equal to.

5 under the root number is approximately equal to.

Naturally, 6 under the root number is equal to 3 under the root number multiplied by 2 under the root number, and the root number under 2 is substituted into the root number 6.

And so on. Nature.

You have to remember the most basic.

Second question.

First of all, it is necessary to know that the arc length is equal to n 360* d

As long as you calculate the central angle corresponding to Xuan, you can calculate it.

Take the arc center as the starting point to make a straight line perpendicular to the Xuan, and then use the Pythagorean theorem to calculate the central angle.

The origin of the root number.

Nowadays, we are all accustomed to using root numbers (e.g., etc.) and find it simple and convenient to use. So, how did the root number come into being and evolve into what it is now?

In ancient times, the Egyptians used the mark " " to indicate the square root. When Indians open the square, they write ka in front of the number of squares to be opened. Arabs use .

Around 1840, the Germans used a dot "."To represent the square root, two points"...means 4 power roots, three dots".

denotes the cube root, e.g., .,3、..3、..

3 represents the square root, the 4th power root, and the cubic root of 3, respectively. By the beginning of the sixteenth century, probably because of the speed of writing, the dot had a slender tail on it, which became " In 1525, in his algebraic works, Ludolph first used the root number, for example, he wrote 4 is 2, 9 is 3, and used 8, 8 to denote , but this writing is not universally recognized.

At the same time, some people use the capital r of the first letter of the Latin radix of the word "root" to indicate the opening operation, followed by the first letter q of the Latin word "square", or the first letter c of "cube", to indicate how many powers it opens. For example, the current , when someone wrote. The present , with the notation of the mathematician Bombelli (1526-1572), can be written?

Among them"?It is equivalent to the parentheses used today, and p is equivalent to the plus sign used today (at that time, even the plus and minus signs "+" were not universal).

It was not until the 17th century that the French mathematician Descartes (1596-1650) was the first to use the root name "" in which Descartes wrote: "If you want to find the square root of , write , if you want to find the cube root of , write ." ”

What are the reasons for this? In order to avoid confusion, Descartes used a horizontal line to connect these terms, and put the root number in front of it (however, it has a small hook more than the root number of Roudolphus) in the current root number form.

The current cube root symbol appeared much later, and it was not until the eighteenth century that the use of symbols was seen in a book, such as the cube root of 25. Later, forms such as root numbers such as and so on were gradually used.

It can be seen from this how difficult it is for the universal adoption of a symbol, it is the result of continuous improvement, selection and elimination of people over a long period of time, and it is the crystallization of the collective wisdom of several families, not a single person made up out of thin air, not falling from the sky.

The root number in the computer is in the form of .

The method of calculating the open root number.

For example, the root number five is now judged to be greater than 2 and less than 3, so the square of the calculation is equal to and greater than 5. So the square taken again is greater than 5. The square of the second square is less than 5, and it is determined that the root number five is approximately equal to!

There are no formulas, only rote memorization.

Connect the center of the circle with the end of the Xuan using the Pythagorean theorem.

The root number is like the antonym of finding the square of several times of a number, for example, the 2nd power of 3 is 9, then the 9 root number 2 is 3.

In secondary school, the calculation of the square is involved, one is to look up the math table, and the other is to use the calculator. The most commonly used solution is to use factorized prime factors to solve the problem. For example, simplifying 1024, because 1024=2 10, so.

1024=2^5=32；Another example is 1256= (2 3*157) 2* (2*157) 2 314

The root number is a mathematical symbol. The root sign is a symbol used to represent the opening operation of a number or an algebraic formula. If a = b, then a is the nth root of b to the nth power or a is the 1 nth power of b.

The open nth power handwriting and typography are denoted by the number or algebraic form written on the left side of the symbol and the area below the horizontal part above the symbol, and cannot go out of bounds.

First of all, the number of squares to be openedFactorization, if anyPrime factorIf there is an exponent, take the even number of them and open them outside the root number.

For example: 20 (2*2*5) 2 2*5) - where the index of 2 is 2, take an even number, that is, 2, put it out, and become 2 5

The Law of Division:

The purpose of division is to find the quotient, but from the dividend.

When you suddenly can't see how much quotient it contains, you can use the method of testing quotient and estimating quotient to see how many divisors are contained in the highest digits of the multiplier (that is, several times of the quotient), and then add the complement number several times from the standard, and the number obtained is the quotient.

Decimals: Where the dividend contains a divisor, 3 times, the period method is:

The dividend contains 1 times the quotient: the complement is added once from the base.

The dividend contains quotient by 2 times: add the complement twice from the base.

The dividend contains 3 times the quotient: add the complement three times from the base.

The method of calculating the open root number.

Summary. 1.Method of opening the root number: factorization. Swap the number for the product of the square and the number.

1.Method of opening the root number: factorization. Swap the number for the product of the square and the number.

The root number is a mathematical symbol. The root number is a symbol used to indicate the blind carrying operation of a group of numbers or an algebraic formula. If a = b, then a is the nth root of b to the nth power or a is 1 nth to the nth power of b.

Refers to the operation of finding the square root of a number, which is the inverse of the power of the square. The power root of n (n is a natural number) of the number a refers to the number where the power of n is equal to a, that is, the number b that is suitable for b to the n power = a

1 From the single digit to the left of the ear answer is a section, if there is a decimal point from the decimal point to the right every two quarters, use the "," sign to separate the sections; 2. Find the perfect square number that is not greater than the number of the first section on the left, which is "quotient"; 3 Subtract the quotient obtained from the first section on the left, and write the second section as the first remainder to the right of their difference. 4. Multiply the quotient by 20 and divide the first remainder to obtain the largest integer as the quotient (if the maximum integer is greater than or equal to 10, use 9 or 8 as the quotient); 5 Multiply the quotient by 20 plus the test quotient and multiply by the test quotient. If the product obtained is less than or equal to the remainder, write this trial quotient after the quotient as a new quotient; If the product obtained is greater than the remainder, the test quotient is reduced one by one and then tried to guess the curve until the product is less than or equal to the remainder; 6 In the same way, keep asking. This method MS is more suitable for people + calculators, and it is very cumbersome to use a computer alone.

Hello, glad to answer for you. Pro, the method of opening the root number is as follows:1

The integer part of the square number is divided into a paragraph every two digits from the single digit to the left, and divided into several segments with an apostrophe, indicating that the square root sought is a few digits. 2.According to the number in the first paragraph on the left, find the number in the highest digit of the square root.

3.Subtract the square of the number on the highest digit from the number of the first stage, and write the number of the second section to the right of their difference to form the first remainder. 4.

Multiply the highest digit obtained by the bureau by 20 to try to divide the first remainder, and the largest integer obtained is used as the test quotient. 5.Use 20 times the highest digit of the quotient plus the quotient and multiply it by the quotient.

If the resulting product is less than or equal to the remainder, the test quotient is the second digit of the square root; If the product obtained is greater than the remainder, reduce the test quotient and try again. 6.In the same way, continue to find the number on the square root.