Talk:Variable (mathematics)

"A variable is a symbol"
The sentence "A variable is a symbol" is blatantly wrong, and I added a reference to confirm this. Just to give one out of many possible examples, the distance from the Earth to the Sun is a variable. It was a variable before mankind existed, and started to denote this variable by symbols. Suppose a particular human decides to denote this quantity by rE, that doesn't suddenly create a new variable. The variable is still the same.Ehrenkater (talk) 10:49, 5 October 2018 (UTC)
 * This article is about variables in mathematics, not about the common meaning of "variable", which is an adjective and not a noun, as it is in mathematics. It is wrong that "the distance from the Earth to the Sun is a variable". The truth is "the distance from the Earth to the Sun is variable, and may be represented, in formulas, by a symbol called a variable". Also, we must take into account that, in modern mathematics, the noun "variable" is widely used for symbols representing quantities that cannot vary. For example, in an equation, such as the quadratic equation, the unknown is generally represented by the variable $x$; this variable can have up to two values, which cannot vary. D.Lazard (talk) 13:36, 5 October 2018 (UTC)

E and Pi are not variables
I found e and π in the list of variables. But they're not variables because they have known values (e ≈ 2.78, π ≈ 3.14). so, why are they here? 2600:8800:5112:7500:B09F:C337:A2AB:2DA0 (talk) 03:48, 11 January 2022 (UTC)
 * It is said in the introduction that a variable may represent any mathematical object. Therefore, it may represent also a constant. I have edited for clarifying this. D.Lazard (talk) 10:50, 11 January 2022 (UTC)


 * it may be true, but if it's really true, then I may or may not think that π and e are not approximately 3.14 and 2.78. 2600:8800:5112:7500:F9EE:B252:FD43:30FC (talk) 07:30, 14 January 2022 (UTC)
 * Correct. You may find other uses of $$\pi$$ and $e$ in projection (mathematics) and Quintic function. D.Lazard (talk) 09:18, 14 January 2022 (UTC)