Can the function $f(x)$ defined by $$ x = f(x)^2 e^{f(x)}$$ for real $x>0$ be expressed in relation to the Lambert W Function?
2026-03-25 16:06:11.1774454771
Generalization of Lambert W function?
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As @Simply Beautiful Art mention in the comments, take square roots of both sides in the equation
$$x=f(x)^2 e^{f(x)} $$
and get
$$\sqrt{x}=f(x) e^{\frac{f(x)}{2}} .$$
Now divide by two both sides
$$\frac{\sqrt{x}}{2}=\frac{f(x)}{2} e^{\frac{f(x)}{2}} $$
Using definition of Lambert W function, we write
$$\frac{f(x)}{2} = W(\pm \sqrt{x}/2) $$
and get
$$f(x) = 2 W(\pm \sqrt{x}/2).$$
As Robert showed in his answer.