Where do math symbols come from? - John David Walters

2,438,257 views ・ 2017-10-30

TED-Ed


μ•„λž˜ μ˜λ¬Έμžλ§‰μ„ λ”λΈ”ν΄λ¦­ν•˜μ‹œλ©΄ μ˜μƒμ΄ μž¬μƒλ©λ‹ˆλ‹€.

λ²ˆμ—­: μ‘° 영호 κ²€ν† : Jihyeon J. Kim
00:07
In the 16th century, the mathematician Robert Recorde
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16세기에 μˆ˜ν•™μžμΈ λ‘œλ²„νŠΈ λ ˆμ½”λ“œλŠ”
00:10
wrote a book called "The Whetstone of Witte"
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"μ§€ν˜œμ˜ 숫돌"μ΄λΌλŠ” 책을 μΌμŠ΅λ‹ˆλ‹€.
00:13
to teach English students algebra.
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영ꡭ ν•™μƒλ“€μ—κ²Œ λŒ€μˆ˜ν•™μ„ κ°€λ₯΄μΉ˜κΈ° μœ„ν•΄μ„œμ˜€μ£ .
00:15
But he was getting tired of writing the words "is equal to" over and over.
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ν•˜μ§€λ§Œ μ§€λ£¨ν•˜κ²Œλ„ " ~와 κ°™λ‹€"λ₯Ό μ“°κ³  또 써야 ν–ˆμŠ΅λ‹ˆλ‹€.
00:21
His solution?
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κ·Έλž˜μ„œ μ–΄λ–»κ²Œ ν–ˆμ„κΉŒμš”?
00:22
He replaced those words with two parallel horizontal line segments
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μˆ˜ν‰μœΌλ‘œ ν‰ν–‰ν•˜κ²Œ 그은 두 μ„ μœΌλ‘œ 이 말듀을 λͺ¨λ‘ λ°”κΏ” μΌμŠ΅λ‹ˆλ‹€.
00:27
because the way he saw it, no two things can be more equal.
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두 개의 ν‰ν–‰μ„ λ§ŒνΌ 같은 것은 μ—†λ‹€κ³  μƒκ°ν–ˆκΈ° λ•Œλ¬Έμ΄μ§€μš”.
00:32
Could he have used four line segments instead of two?
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μ„  2개 λŒ€μ‹  4개λ₯Ό μ΄μš©ν•΄λ„ λ˜μ—ˆμ„κΉŒμš”?
00:34
Of course.
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물둠이죠.
00:36
Could he have used vertical line segments?
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μ„Έλ‘œ 선을 μ΄μš©ν•  μˆ˜λ„ μžˆμ—ˆλ‚˜μš”?
00:38
In fact, some people did.
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사싀, λͺ‡λͺ‡ μ‚¬λžŒλ“€μ€ κ·Έλ ‡κ²Œ 쓰기도 ν–ˆμŠ΅λ‹ˆλ‹€.
00:40
There's no reason why the equals sign had to look the way it does today.
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λ“±ν˜Έκ°€ μ˜€λŠ˜λ‚ μ˜ ν˜•μ‹μœΌλ‘œ κ΅³μ–΄μ§€κ²Œ 된 μ΄μœ λŠ” μ—†μŠ΅λ‹ˆλ‹€.
00:44
At some point, it just caught on, sort of like a meme.
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μ–΄λ–»κ²Œ 보면, 단지 μœ ν–‰μ΄μ—ˆκ³ , λ”°λΌν•˜κΈ° 같은 κ±°μ˜€μ£ .
00:48
More and more mathematicians began to use it,
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점점 더 μˆ˜ν•™μžλ“€μ΄ 이λ₯Ό μ‚¬μš©ν•˜κΈ° μ‹œμž‘ν–ˆκ³ ,
00:50
and eventually, it became a standard symbol for equality.
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λ§ˆμΉ¨λ‚΄λŠ” κ°™μŒμ„ λ‚˜νƒ€λ‚΄λŠ” ν‘œμ€€ 기호둜 자리작게 λ˜μ—ˆμŠ΅λ‹ˆλ‹€.
00:55
Math is full of symbols.
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μˆ˜ν•™μ€ 기호둜 κ°€λ“ν•©λ‹ˆλ‹€.
00:56
Lines,
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μ„ ,
00:57
dots,
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점,
00:58
arrows,
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ν™”μ‚΄ν‘œ,
00:59
English letters,
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영문자,
01:00
Greek letters,
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그리슀 문자,
01:01
superscripts,
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μœ—μ²¨μž,
01:02
subscripts.
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μ•„λž«μ²¨μž.
01:03
It can look like an illegible jumble.
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읽기 μ–΄λ ΅κ²Œ 마ꡬ μ„žμ–΄ 놓은 것 κ°™μ£ .
01:05
It's normal to find this wealth of symbols a little intimidating
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μ΄λ ‡κ²Œ λ‹€μ–‘ν•œ λΆ€ν˜Έμ— 겁을 λ¨ΉλŠ” 것은 μ–΄μ°Œλ³΄λ©΄ λ‹Ήμ—°ν•©λ‹ˆλ‹€.
01:09
and to wonder where they all came from.
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κ·Έ λΆ€ν˜Έκ°€ μ–΄λ””μ„œ μ™”λŠ”μ§€λ„ κΆκΈˆν•΄ ν•˜λŠ” κ²ƒλ„μš”.
01:13
Sometimes, as Recorde himself noted about his equals sign,
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λ•Œλ‘œλŠ” λ ˆμ½”λ“œκ°€ λ“±ν˜Έμ— λŒ€ν•΄ μ„€λͺ…ν•œ κ²ƒμ²˜λŸΌ
01:16
there's an apt conformity between the symbol and what it represents.
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κΈ°ν˜Έμ™€ κΈ°ν˜Έκ°€ λ‚˜νƒ€λ‚΄λŠ” λŒ€μƒμ΄ 연관이 μžˆλŠ” κ²½μš°λ„ μžˆμŠ΅λ‹ˆλ‹€.
01:21
Another example of that is the plus sign for addition,
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이에 λŒ€ν•œ μ˜ˆλ‘œλŠ” λ§μ…ˆμ„ λ‚˜νƒ€λ‚΄λŠ” λ”ν•˜κΈ° κΈ°ν˜Έκ°€ μžˆμŠ΅λ‹ˆλ‹€.
01:25
which originated from a condensing of the Latin word et meaning and.
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이 κΈ°ν˜ΈλŠ” "그리고"λ₯Ό λœ»ν•˜λŠ” 라틴 문자 et 을 μΆ•μ•½ν•œ κ²ƒμž…λ‹ˆλ‹€.
01:30
Sometimes, however, the choice of symbol is more arbitrary,
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ν•˜μ§€λ§Œ λ•Œλ‘œλŠ” λ‹€μ†Œ μ œλ©‹λŒ€λ‘œ 기호λ₯Ό μ„ νƒν•˜κΈ°λ„ ν•©λ‹ˆλ‹€.
01:33
such as when a mathematician named Christian Kramp
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κ°€λ Ή ν¬λ¦¬μŠ€ν‹°μ•ˆ ν¬λž¨ν”„λΌλŠ” μˆ˜ν•™μžλŠ”
01:36
introduced the exclamation mark for factorials
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νŒ©ν† λ¦¬μ–Όλ₯Ό λŠλ‚Œν‘œλ‘œ ν‘œκΈ°ν–ˆμŠ΅λ‹ˆλ‹€.
01:40
just because he needed a shorthand for expressions like this.
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단지 이런 κΈ΄ 계산듀을 쀄여쓰고 μ‹Άμ—ˆκΈ° λ•Œλ¬Έμ΄μ§€μš”.
이런 μ‹μœΌλ‘œμš”.
01:44
In fact, all of these symbols were invented or adopted
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사싀, 이 λͺ¨λ“  κΈ°ν˜ΈλŠ” μˆ˜ν•™μžλ“€μ΄ 발λͺ…ν•˜κ±°λ‚˜ μ±„νƒν•œ κ²ƒμž…λ‹ˆλ‹€.
01:48
by mathematicians who wanted to avoid repeating themselves
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λ°˜λ³΅ν•΄μ„œ μ‚¬μš©ν•˜λŠ” κ±Έ ν”Όν•˜κ³ 
01:51
or having to use a lot of words to write out mathematical ideas.
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κΈ΄ 단어λ₯Ό μ‚¬μš©ν•˜μ§€ μ•Šκ³ , μˆ˜ν•™ κ°œλ…μ„ μž‘μ„± ν•˜λ €κ³  말이죠.
01:57
Many of the symbols used in mathematics are letters,
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μˆ˜ν•™μ—μ„œ μ‚¬μš© λ˜λŠ” λ§Žμ€ κΈ°ν˜ΈλŠ” λŒ€λΆ€λΆ„
01:59
usually from the Latin alphabet or Greek.
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라틴 μ•ŒνŒŒλ²³μ΄λ‚˜ 그리슀 λ¬Έμžμž…λ‹ˆλ‹€.
02:03
Characters are often found representing quantities that are unknown,
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λ¬ΈμžλŠ” μ•Œ 수 μ—†λŠ” μˆ˜λŸ‰μ„ λ‚˜νƒ€λ‚΄κΈ°λ„ ν•˜κ³ ,
02:08
and the relationships between variables.
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λ³€μˆ˜λ“€ κ°„μ˜ 관계λ₯Ό λ‚˜νƒ€λ‚΄κΈ°λ„ ν•©λ‹ˆλ‹€.
02:11
They also stand in for specific numbers that show up frequently
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자주 λ‚˜νƒ€λ‚˜λŠ” νŠΉμ • 숫자λ₯Ό λŒ€μ‹ ν•˜κΈ°λ„ ν•˜μ§€λ§Œ
02:15
but would be cumbersome or impossible to fully write out in decimal form.
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κΈΈκ³  λ³΅μž‘ν•˜κ±°λ‚˜ μ‹­μ§„μˆ˜ ν˜•μ‹μœΌλ‘œ μ“°κΈ° νž˜λ“  수λ₯Ό λŒ€μ‹ ν•˜κΈ°λ„ ν•©λ‹ˆλ‹€.
02:21
Sets of numbers and whole equations can be represented with letters, too.
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μˆ«μžλ“€μ˜ μ‘°ν•©μ΄λ‚˜ λͺ¨λ“  방정식도 μ—­μ‹œ 문자둜 λŒ€μ²΄ν•  수 μžˆμŠ΅λ‹ˆλ‹€.
02:26
Other symbols are used to represent operations.
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연산을 λ‚˜νƒ€λ‚΄κΈ° μœ„ν•΄ 기호λ₯Ό μ‚¬μš©ν•˜κΈ°λ„ ν•©λ‹ˆλ‹€.
02:29
Some of these are especially valuable as shorthand
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λͺ‡λͺ‡μ€ μ•½μ–΄λ‘œ 특히 κ·€ν•˜κ²Œ μ‚¬μš© λ˜λŠ”λ°,
02:32
because they condense repeated operations into a single expression.
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λ°˜λ³΅λ˜λŠ” 연산을 ν•¨μΆ•ν•΄μ„œ 기호 ν•˜λ‚˜λ‘œ λ‚˜νƒ€λ‚΄κΈ° λ•Œλ¬Έμž…λ‹ˆλ‹€.
02:36
The repeated addition of the same number is abbreviated with a multiplication sign
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같은 수λ₯Ό λ”ν•˜λŠ” λ°˜λ³΅ν•΄μ„œ λ”ν•˜λŠ” 연산은 κ°„λ‹¨ν•˜κ²Œ κ³±μ…ˆ 기호 ν‘œν˜„ν•  수 있죠.
02:41
so it doesn't take up more space than it has to.
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μ˜ˆμ „μ²˜λŸΌ λ§Žμ€ 곡간을 차지할 ν•„μš”λ„ μ—†μŠ΅λ‹ˆλ‹€.
02:44
A number multiplied by itself is indicated with an exponent
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같은 수λ₯Ό λ°˜λ³΅ν•΄μ„œ κ³±ν•˜λŠ” 건 μ§€μˆ˜λ‘œ λ‚˜νƒ€λ‚Ό 수 있고,
02:47
that tells you how many times to repeat the operation.
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이 μ§€μˆ˜λŠ” κ³±μ…ˆμ„ λͺ‡λ²ˆ λ°˜λ³΅ν•˜λŠ”μ§€ μ•Œλ € μ€λ‹ˆλ‹€.
02:51
And a long string of sequential terms added together
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순차적인 κ·œμΉ™μœΌλ‘œ λ§μ…ˆμ„ ν•˜λŠ” κΈ΄ 연산은
02:54
is collapsed into a capital sigma.
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λŒ€λ¬Έμž μ‹œκ·Έλ§ˆ 기호둜 쀄여 μ”λ‹ˆλ‹€.
02:57
These symbols shorten lengthy calculations to smaller terms
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μ΄λ ‡κ²Œ κΈ°ν˜ΈλŠ” κΈ΄ 연산을 짧은 μˆ˜μ‹μœΌλ‘œ μ€„μ—¬μ„œ
03:01
that are much easier to manipulate.
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보닀 μ‰½κ²Œ μ—°μ‚°ν•  수 있게 ν•΄μ£Όμ£ .
03:05
Symbols can also provide succinct instructions
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κΈ°ν˜ΈλŠ” 간단 λͺ…λ£Œν•˜κ²Œ 보여 μ€λ‹ˆλ‹€.
03:07
about how to perform calculations.
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μ–΄λ–€ λ°©λ²•μœΌλ‘œ 계산을 할지 말이죠.
03:10
Consider the following set of operations on a number.
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λ‹€μŒμ˜ 연산듀을 λ΄…μ‹œλ‹€.
03:13
Take some number that you're thinking of,
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숫자 ν•˜λ‚˜λ₯Ό μƒκ°ν•˜μ„Έμš”.
03:15
multiply it by two,
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κ·Έκ±Έ λ‘λ²ˆ κ³±ν•˜κ³ ,
03:17
subtract one from the result,
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κ·Έ κ²°κ³Όμ—μ„œ ν•˜λ‚˜λ₯Ό λΉΌκ³ ,
03:18
multiply the result of that by itself,
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κ·Έ κ²°κ³Ό κ°’κ³Ό 같은 값을 κ³±ν•˜κ³ ,
03:21
divide the result of that by three,
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κ·Έ κ²°κ³Όλ₯Ό 3으둜 λ‚˜λˆ„κ³ ,
03:23
and then add one to get the final output.
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그리고 ν•˜λ‚˜λ₯Ό λ”ν•˜λ©΄ μ΅œμ’… κ²°κ³Όκ°€ λ‚˜μ˜΅λ‹ˆλ‹€.
03:26
Without our symbols and conventions, we'd be faced with this block of text.
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μˆ˜ν•™ κΈ°ν˜Έμ™€ κ·œμΉ™ μ—†μ—ˆλ‹€λ©΄ 이런 문자 덩어리λ₯Ό 썼겠죠.
03:32
With them, we have a compact, elegant expression.
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μˆ˜ν•™ 기호 덕뢄에 ν‘œν˜„μ΄ μ΄λ ‡κ²Œ κ°„κ²°ν•˜κ³  μš°μ•„ν•΄μ‘ŒμŠ΅λ‹ˆλ‹€.
03:35
Sometimes, as with equals,
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가끔 λ“±ν˜Έλ₯Ό 보면,
03:37
these symbols communicate meaning through form.
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λ“±μ‹μ˜ 의미λ₯Ό μ „λ‹¬ν•©λ‹ˆλ‹€.
03:40
Many, however, are arbitrary.
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ν•˜μ§€λ§Œ λŒ€λΆ€λΆ„μ€ μ–΄λ–€ μˆ˜λ‚˜ 연산을 λŒ€μ²΄ν•˜μ£ .
03:43
Understanding them is a matter of memorizing what they mean
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λ“±μ‹μ˜ μ΄ν•΄λŠ” κΈ°ν˜Έκ°€ λœ»ν•˜λŠ” κ±Έ κΈ°μ–΅ν•˜κ³ ,
03:46
and applying them in different contexts until they stick, as with any language.
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μ–΄λŠ μ–Έμ–΄μ—μ„œκ±΄, 이듀이 μ“°μ΄λŠ” λ‹€λ₯Έ 상황에 μ μš©ν•˜λŠ” λ¬Έμ œμž…λ‹ˆλ‹€.
03:52
If we were to encounter an alien civilization,
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μš°λ¦¬κ°€ 외계 λ¬Έλͺ…을 λ§Œλ‚˜κ²Œ 되면
03:54
they'd probably have a totally different set of symbols.
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외계인은 μ™„μ „νžˆ λ‹€λ₯Έ ν˜•νƒœμ˜ κΈ°ν˜Έλ“€μ„ μ‚¬μš©ν•  것 μž…λ‹ˆλ‹€.
03:58
But if they think anything like us, they'd probably have symbols.
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ν•˜μ§€λ§Œ 우리처럼 μƒκ°ν•œλ‹€λ©΄, 기호λ₯Ό 가지고 있겠죠.
04:04
And their symbols may even correspond directly to ours.
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심지어 κ·Έλ“€μ˜ κΈ°ν˜ΈλŠ” 우리 κΈ°ν˜Έμ™€ μΌλŒ€μΌλ‘œ 맞좜 수 μžˆμ„ κ²λ‹ˆλ‹€.
04:08
They'd have their own multiplication sign,
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외계인듀도 μžμ‹ λ“€λ§Œμ˜ κΈ°ν˜Έκ°€ 있겠죠, κ³±μ…ˆ 기호,
04:10
symbol for pi,
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파이 기호, 그리고 λ¬Όλ‘  λ“±ν˜ΈκΉŒμ§€λ„μš”.
04:12
and, of course, equals.
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이 μ›Ήμ‚¬μ΄νŠΈ 정보

이 μ‚¬μ΄νŠΈλŠ” μ˜μ–΄ ν•™μŠ΅μ— μœ μš©ν•œ YouTube λ™μ˜μƒμ„ μ†Œκ°œν•©λ‹ˆλ‹€. μ „ 세계 졜고의 μ„ μƒλ‹˜λ“€μ΄ κ°€λ₯΄μΉ˜λŠ” μ˜μ–΄ μˆ˜μ—…μ„ 보게 될 κ²ƒμž…λ‹ˆλ‹€. 각 λ™μ˜μƒ νŽ˜μ΄μ§€μ— ν‘œμ‹œλ˜λŠ” μ˜μ–΄ μžλ§‰μ„ 더블 ν΄λ¦­ν•˜λ©΄ κ·Έκ³³μ—μ„œ λ™μ˜μƒμ΄ μž¬μƒλ©λ‹ˆλ‹€. λΉ„λ””μ˜€ μž¬μƒμ— 맞좰 μžλ§‰μ΄ μŠ€ν¬λ‘€λ©λ‹ˆλ‹€. μ˜κ²¬μ΄λ‚˜ μš”μ²­μ΄ μžˆλŠ” 경우 이 문의 양식을 μ‚¬μš©ν•˜μ—¬ λ¬Έμ˜ν•˜μ‹­μ‹œμ˜€.

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