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Math Question: What is an imaginary number?
In mathematics, if the square of a number is negative, then the number is imaginary. All imaginary numbers are complex numbers.

The word "imaginary number" was invented by Descartes, a famous mathematician in17th century, because the concept at that time thought it was a nonexistent real number. Later, it was found that the imaginary number can correspond to the vertical axis on the plane, which is as real as the real number corresponding to the horizontal axis on the plane. The plane composed of imaginary axis and real axis is called complex plane, and each point on the complex plane corresponds to a complex number.

Imaginary symbol

1777, the Swiss mathematician Euler began to express imaginary units with the symbol i=√(- 1). Then people organically combine imaginary numbers with real numbers and write them in the form of a+bi (both a and b are real numbers), which is called complex numbers.

History of imaginary number

Because imaginary number has entered the field of numbers, people know nothing about its practical use, and there seems to be no quantity expressed by complex number in real life. Therefore, for a long time, people have all kinds of doubts and misunderstandings about imaginary numbers. Descartes' original intention of saying "imaginary number" means that he is false; Leibniz thought at the beginning of18th century: "imaginary number is a wonderful and strange hiding place of God, which is almost an amphibian with and without existence." Although Euler used imaginary numbers in many places, he also said that all mathematical formulas in the form of √(- 1) and √(-2) are impossible and purely illusory.

After Euler, the Norwegian surveyor Wiezell proposed that the complex number a+bi be represented by points (a, b) on the plane. Later, Gauss put forward the concept of complex plane, which finally made complex numbers have a foothold and opened the way for the application of complex numbers. At present, vectors (vectors) are generally represented by complex numbers, which are widely used in mechanics, cartography, aviation and other fields. Imaginary number shows its rich content more and more, really: imaginary number is not empty.

Numbers that do not represent the real number. For example, the numbers such as 1, 3, 5, 9, 100, 1,000 and 10,000 in the following example are imaginary numbers. Take one as ten | groups of three or five | Do everything possible | Colorful | Nine Niu Yi hairs | Longsheng Jiuzi | I don't know the taste of March meat |.

Describe imaginary number

imaginary number

Lawrence Mark Lesser (Armstrong Atlantic State College) Translation: Xu Guoqiang.

Since ancient times, the word ai can be used.

Everyone was surprised when asked. Where can there be real energy in life?

Oh, I tried to adjust it. I was shocked and patted the night light.

With or without transistors, AC circuits are willing to be salty.

If you ask ridiculous questions, negative values will increase your doubts.

Emotions are used to listening at first, which is related to negative numbers.

It's a bit complicated to integrate into the academic field.

But looking at the geometric triangle, the lush wormwood also means this [1].

Translated from the online journal of humanities mathematics, 22 issues, 48 pages.

imaginary

Lawrence Mark Lesser

Armstrong Atlantic State University

Imaginary number, multiple of I

Everyone wants to know, "Do they use it in real life?"

Ok, try the amplifier I am using now-AC!

You said it was ridiculous,

The root of this negative one.

But the same thing has been heard.

About the number minus one!

Imaginary numbers are a little complicated,

But in real mathematics, everything is interrelated:

Geometry, triangle, and call all look at "I am to me"!

Excerpted from Network Journal of Humanities Mathematics # 22, page 48.

Science Times, February 14, 2003, Science Weekend [①] See "I to I" refers to the application of visible imaginary symbols, and the homonym pun "see eye to eye" means agreement.