Why is X Generally the Unknown in Mathematics?

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Algebra was born in the Middle East, during the Golden Age of medieval Islamic civilization (750 to 1258 AD), and its early form can be seen in the work of Muhammad Al-Khwarizmi and his 9th century book, Kitab al-jabr wal-muqabala (al-jabr later morphing into algebra in English). During this heyday, Muslim rule and culture had expanded onto the Iberian Peninsula, where the Moors encouraged scholarship in the sciences and math.

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[TodayIFoundOut]

Now that you know why X is generally the unknown in mathematics check out this video and find out the answer to the question- When Did People Start Using Punctuation?:

[captaincokecan]

Like the great 'philosopher' of our time DMX said. "X is going to give it to you" ... That said I am unsure if he delivers outside of business hours. check the terms and conditions i guess.

[squirrel]

I don't like ads, but I super liked that ad because we got to hear your more hipster regular dude voice in contrast to your professional polite alter ego ^_^

[jonstfrancis]

Mediaeval Spanish did have the sh sound and it was written with the letter X. So the use of X for Arabic shín makes perfect sense.

[waylandgriffith]

I'm sure others have written this but you have a big "oopsie" in this video. DesCartes said "cogito ergo sum". Your version, "cognito ergo sum" means "I hide therefore I am". Other than that, I even enjoyed the ad.

[finno-pxof]

I’m doing math study, I take 1 break and this is the first video that pops up :)

[midnightman]

Somehow Simon makes an ad fun to watch, ah I love this channel!

[lunarotimas]

To get your item to focus; put your other hand behind it when you bring it close. It basically makes the background a solid colour and allows your camera to focus on the one item.

Hope this helps!

[bd_ART]

1:18
It’s called “Al-Shai’ “ not Alshalan

[Geferulf_TAS]

I always found it to be such a pain that X was the unknown back in grade school, it always made algebraic multiplication a pain!

[jacobarmstrong]

the at home parts are great! wish Simon would do it more/longer

[Synos]

Next on "Today I Found Out": Why in the Queens English its pronounced 'zed' and in American English, 'zee' Along with other spelling and pronunciation differences across the pond.

[Twewy]

8:24 It is "Cogito, ergo sum", not 'cognito'

[lauraheyman]

I loved your "Dollar Shave Club" ad. Well done! 🥰🥰🥰

[blackstonerzein]

Being Arabic Myself I Can Confirm That "ِAl-Shalan" Does *NOT* Mean The Unknown Thing In Arabic

[GeoffBernard]

I'm jealous of that shower.

BTW - I really enjoyed this form of ad. Much better than being blasted to a commercial right in the middle of a video.

[rfpowerdude]

Simon, as an engineer, I found your final bonus fact about the education comparisons between countries much more intriguing than the rest of the video. Glad I watched to the end! Don't get me wrong, I enjoyed this one in its entirety and all of your videos, but this bonus fact just illustrates a possible need for an entire video dedicated to just this one subject. It shows how important it is to assess the state of our education system in the USA. Thanks for the great channel!

[ThorirPP]

I have noticed one glaring flaw in what you said: X being used by the Spanish to represent the sh would be because X was used in Spanish (Old Spanish to be more precise, Spanish has changed a bit since then) to represent that very sound.
Unlike what you say here, this X wasn't from Greek Chi and didn't have a "ck" sound, but rather came from the Latin X which had a ks sound in Latin but was used for a sh sound by the time of Old Spanish.

Of course later both the sh sound of X and the zh sound of J in spanish merged and became later a kh sound (very similar to a h sound), which happens to be the same sound that the Greek letter Chi has in modern Greek pronunciation. But not only is that just a coincidence but other than in few proper names and Latin American spellings that didn't change, X that was sh has been replaced by J and X is only used today for the classical ks sound.

Basically there is a very simple reason why X would be used for the Arabic sh sound: X was the Spanish way to write that sound in Spanish. Nothing to complicated here.

[CateOwen]

One day I was reading the YouTube comments and someone said "Simon Whistler is daddy"; now I can't get it out of my head. Every time I see him I think, Simon Whistler is daddy, so that's a thing now.

[SgtWiking]

2:53 "X? Why X? Give her the D."
-René Descartes 1596-1650