Vowel in Creek, the letter "V" stands for . There is not necessarily a direct one-to-one correspondence between the vowel sounds of a language and the vowel letters. Many languages that use a form of the Latin alphabet have more vowel sounds than can be represented by the standard set of five vowel letters. In English spelling, the five letters "A" "E" "I" "O" and "U" can represent a variety of vowel sounds, while the letter "Y" frequently represents vowels (as in e.g., "gym", "happy", or the diphthongs in "cry", "thyme"); "W" is used in representing some diphthongs (as in "cow")
Radical symbol are both imaginary numbers, and the square root symbol refers to the principal square root, the one with positive imaginary part. For the definition of the principal square root of other complex numbers, see Square root#Principal square root of a complex number. The origin of the root symbol √ is largely speculative. Some sources imply that the symbol was first used by Arab mathematicians. One of those mathematicians was Abū al-Hasan ibn Alī al-Qalasādī (1421–1486). Legend has it that it was taken from the Arabic letter "" ("ǧīm", which is the first letter in the Arabic word "" ("jadhir", meaning