2
$\begingroup$

I want to say that a variable $y$ is a function of $x$.

But I don't want to name the function, like:

$y = f(x)$

So is there a notation for the phrase "$y$ is a function of $x$" which does not specify a name for the function?

(A related but distinct question: Notation: is there a symbol for "not a function of"?)

$\endgroup$
  • 1
    $\begingroup$ You could explicitly state the dependence of $y$ on $x$ by simply writing $y(x)$ instead of just $y$. $\endgroup$ – Edward Evans Nov 14 '16 at 22:42
  • 2
    $\begingroup$ Why are you against naming the function? I don't understand how that could negatively impact anything... $\endgroup$ – JMoravitz Nov 14 '16 at 22:45
  • 2
    $\begingroup$ Why do you not want to say "$y$ is a function of $x$" in words? $\endgroup$ – GEdgar Nov 14 '16 at 22:50
  • $\begingroup$ It is a slight abuse of notation, but you might write $y = y(x)$ to say that $y$ depends on $x$. It is especially common to see when there are a lot of nested quantifiers and people want to highlight which parameter depends on what. $\endgroup$ – Jakub Konieczny Nov 14 '16 at 22:56
  • 1
    $\begingroup$ What exactly do you mean with "$y$ is a function of $x$"? Because if you just mean "there exists a function $f$ such that $y=f(x)$", then everything is a function of $x$. For example, $42$ is a function of $x$, namely the constant function $f(x)=42$. $\endgroup$ – celtschk Nov 14 '16 at 22:59

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.