Constant A constant is a value that does not change. Commonly, a constant will be a real number, but can sometimes be written as a variable. When written as a variable, a constant is commonly denoted as c to represent a fixed value. Example y = 5 x + 4 In the function above, 4 is a constant. The 5 is a fixed number, but it is more appropriate to call it a coefficient because it is multiplied by x . Example y = 9 The term "constant" may also refer to a constant function, or a function whose output value is the same for every input value. The function above is a constant function. Example e,π, i, etc. Some constants are given special symbols because they represent sign...