• # Why is it that the alphabets X and Y always considered?

In school when we were asked to find the missing figure, we will find it by putting X as the missing value. If two values are to be found, then it is always X and Y. Even today, when we do not know the name of a person, we refer it to as Mr. X.

Even in a graph, we have X-axis and Y-axis. Later when we studied chromosomes, we learned about X and Y chromosomes. Out of the 26 alphabets, why is it that only X and Y is given so much importance? I agree that A and B are also used at times like in formulas but not as much as X and Y.

Is there anything in particular with these alphabets? Have you ever had this doubt?
• Chitra,
A very good thought provoking thread from you. It is the cross that matters. X and Y have the good four and three crosses unlike any other English alphabets.

No life without Sun

• Very interesting. X and Y weren't present in Greek alphabets. So ancient Greeks used alpha and beta to solve algebra.
English inculcated x and Y much later in 13 or 14th century probably.
So the mathematicians found the letters x and y better to be used than a and b .
Because x and y don't begin many words. So they're flashy.

Honestly, it doesn't matter. You can use any alphabet.

The stronger a light shines the darker are the shadows around it.

• A unique way of questioning or reasoning. Didn't think much about this. Learn't from google that As far as chromosomes go, the chromosome X resembled letter X hence, labelled as X, then y followed x, hence the name chromosome Y, that's what everyone says. Historians believe it goes back to the ancient times wherein ál-shalan in Arabic meant unknown. This, in Greek, became chi and then passed on to other languages wherein unknown entity was labelled as 'X'.

• The alphabets X, Y, Z are always used to represent variables and A, B, C for constants in mathematical literature. In English language (in literature) from the very beginning the letter had appeared to represent unknown. Of course why it was used is not clearly known. In dictionary it is given: X, a person, thing, agency, factor, etc. , of unknown identity.
T.M.Sankaran
Gold Member ISC

• A very good question. X and Y. Both the letters are very rarely used as a starting letter of any word. So these words starting with this letters are very unknown. So all unknown things and persons are called X and Y. This is one of the reasons for using them. There is another point I think is these are the three last letters in the English alphabets. To know 100% of any subject. When you don't know something because of the lost leg of alphabets, we use them for addressing them. Coming to chromosomes they say X chromosomes are in the shape of X. That is why they are called as X. Anyhow the reasons X and Y do not know.
drrao
always confident