Matematikte bilinmeyen sembolü neden X'tir. Merak etmiş miydiniz? Neden "x" ? Merak etmiş miydiniz, matematikte bilinemeyene neden x deriz, neden k degil? In mathematics: x commonly represents an unknown variable. Even though any letter can be used, x is the most common by far. This usage can be traced back to the Arabic word say' = "thing", which in translated algebra texts and similar was taken into Old Spanish with the pronunciation "sei", which was written xei, which was soon habitually abbreviated to x. But some sources say that this x is an abbreviation of Latin causa which was a translation of Arabic . That started the habit of using letters to represent quantities in algebra. Yani diyor ki: Bir İslam bilimcisi cebir kitabı yazarken bilinmeyeni "şey" olarak belirtmiş. Kitap İspanyolca'ya çevrilirken "şey"i "xay" olarak çevirmişler. Sonra kısalıp x kalmış...