Why Does "X" Represent the Unknown?

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YouTube / TED

We use "x" to represent unknown quantities all the time. It appears in algebra (solve for x), but also in culture (The X-Files, X-Men, X Prize, and so on). But how did we collectively settle on that one mysterious letter?

In this four-minute video, Terry Moore takes us on a brief linguistic journey explaining how this came to be. Have a look:

If you want the shortest possible version, the progression is from the Arabic شيء for "the unknown thing" to the Greek χ and then to the Latin x. If you'd like to see the transcript or different subtitles, head over to the TED site.

Note: Moore gave a talk some years back on how to tie your shoes. Worth a look!

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June 10, 2014 - 12:21pm
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