Variables are usually writen as lower-case letters.
Usually, yes.
As written in lower case in this font (as waist), 2: the letters w and iIf written in upper case in this font (as WAIST), 4: the letters W, A, I and T
It is usually the regression coefficient: a measure of the degree to which two variables change in agreement with one another.
Not sure how the upper case and lower case letters interact. If that can be ignored then rj.Not sure how the upper case and lower case letters interact. If that can be ignored then rj.Not sure how the upper case and lower case letters interact. If that can be ignored then rj.Not sure how the upper case and lower case letters interact. If that can be ignored then rj.
In mathematics, a coefficient is a multiplicative factor in some term of an expression (or of a series); it is usually a number, but in any case does not involve any variables of the expression.
Usually, yes.
No particular reason. It is simply a convention with no rationale.
They orginated as quickly written versions of upper case letters.
As written in lower case in this font (as waist), 2: the letters w and iIf written in upper case in this font (as WAIST), 4: the letters W, A, I and T
The variables in such expressions are letters, or some other special symbol (for example, Greek letters, or a combination of letters) - in this case, it's "t".
The acceptable convention says uppercase letters are used for sets and matrices and lowercase letters are for variables, constants and vectors. Greek letters are mainly used for constants, such as pi=3.14 and e=2.718.
b.i.d means two times a day, usually written in lower case letters. Three times a day is t.i.d., four times a day is q.i.d.
It is usually the regression coefficient: a measure of the degree to which two variables change in agreement with one another.
Upper case letters are letters which are in capital format. You can define upper case letters by saying big letters. You can switch to upper case letters by holding shift and/or typing letters while caps lock key on. Lower case letters are letters which are not capital and can be defined by not applying Shift.
The variables of this equation are your letters: a, b, and c. Variables merely stand in an equation to represent values that we don't know. "Solving" an equation is the process by which we uncover those values. In this particular case, since there are three variables, we cannot discover their values unless we have two other equivalent equations (a system of equations).
A variable falls under the category of "Python identifier". SUch an identifier must start with a letter (uppercase or lowercase) or an underscore, followed by zero or more letters, underscores, and digits. Note that Python is case-sensitive; for example, myvariable, MyVariable, and MYVARIABLE would be treated as three different variables.
It depends on the situation. Sometimes we have an equation like: X - 14 = 7, in which we can solve for the letter (in this case, X, which equals 21). Sometimes they are intended to be variables: Y = X3-17X + 4, where the letters may be many numbers, but are restricted when other variables are known. Other times, letters refer to specific constants: e = approximately 2.718281828. pi = approximately 3.141592654. i = sqrt(-1) and is imaginary.