shift key
I'm assuming your looking for a password, a mixed case letter is a word that contains an upper case, and lower case letter. Example: Queen. I used Q as upper case and the rest as lower case. :)
Qboth upper- and lower-case
The electrical symbol for a continuous or r.m.s. currentis an italic, upper-case, letter I. The symbol for an instantaneous value of current is an italic, lower-case, letter i.The symbol for its SI unit of measurement, the ampere, is an upright, upper-case, letter A.
upper case Σ, lower case σ. In maths, the upper case is used when describing sums and the lower case when referring to standard deviations. It's the 18th letter of the Greek alphabet and has an s sound.
It is usually the Greek letter delta: both the upper and lower case versions are used.
It is called "unicase", a capital letter is referred to as a "majiscule". The terms "lower case" and "upper case" are used as well, but that usually refers to the characters on a computer keyboard.
Upper and lower case came from when everything used to be printed by hand. The letters would be inside of a brief case. The upper case would be kept on the top of the case and the lower case on the bottom.
The lower case letter in the symbol represents the subshell that the electron is in. It is a way to indicate the energy level and shape of the electron's orbit. Upper case letters are used for the element's name, while lower case letters are used for subshell designation.
Upper case means 'capital', as in G rather than g. Alpha is the first letter of the Greek alphabet. I may be able to get special characters in the answer, but I do not know how. Look up Greek Alphabet, and you will have your answer soon.
Lowercase and upper case letters refer to how a letter is written - as a capital letter ("A" for example) or as a small, lowercase, letter ("a" for example). Here are all the capital letters in the alphabet: ABCDEFGHIJKLMNOPQRSTUVWXYZ Here are the same letters as lowercase: abcdefghijklmnopqrstuvwxyz Upper case (capital) letters are used to begin sentences and for proper nouns, such as names.
There is no history, since any letter can be used. The letters can be from the Greek or Roman or other alphabets, they can be upper case or lower case.
The shift key on a computer has more than one use. The shift key is used to enter upper case in text as well as some other upper characters. It is also used to perform certain functions in Windows.