Step 1 :The question is asking for the composition of the functions f and g, denoted as \((f \circ g)(x)\). This means we need to substitute \(g(x)\) into \(f(x)\). In this case, \(g(x) = \frac{1}{9} x\), so we need to substitute this into \(f(x) = 9x\).
Step 2 :The result shows that \((f \circ g)(x) = x\). This means that when we substitute \(g(x)\) into \(f(x)\), we get back the original input x.
Step 3 :Final Answer: \((f \circ g)(x)=\boxed{x}\)