Answer:
[tex]\large\boxed{Domain:\ x\in\left(0;\ \dfrac{1}{4}\right>\to0<x\leq\dfrac{1}{4}}[/tex]
Step-by-step explanation:
[tex]f(x)=\sqrt{x-1},\ g(x)=\dfrac{1}{4x}\\\\f\bigg(g(x)\bigg)-\text{instead of x in the function equation f(x) put}\ \dfrac{1}{4x}:\\\\f\bigg(g(x)\bigg)=\sqrt{\dfrac{1}{4x}-1}=\sqrt{\dfrac{1}{4x}-\dfrac{4x}{4x}}=\sqrt{\dfrac{1-4x}{4x}}\\\\\text{The domain}\ D:\\\\\dfrac{1-4x}{4x}\geq0\ \wedge\ 4x\neq0\\\\\dfrac{1-4x}{4x}\geq0\iff(1-4x)(4x)\geq0\\\\1-4x=0\to4x=1\to x=\dfrac{1}{4}\\\\4x=0\to x=0\\(look\ at\ the\ picture)\\\\(1)\qquadx\in\left<0,\ \dfrac{1}{4}\right>\\\\\\4x\neq0\qquad\text{divide both sides by 4}\\\\(2)\qquad x\neq0[/tex]
[tex]\text{From}\ (1)\ \text{and}\ (2)\ \text{We have}\ x\in\left(0,\ \dfrac{1}{4}\right>[/tex]
