I want to say that $x=1$ or $x=-1$, but we don't know which one (or we could possibly calculate it, but it is complicated). Anyhow, for my future proof all I need to know is that $x$ is either $1$ or $-1$.
Is it OK to write it as $x=\pm 1$ ?
I am asking because it seems that meaning here is different from for example when we use $\pm$ in the formula of roots of quadratic equations.
If I can't use $\pm$, then is there some other way I can denote it?