If, a > 0 and n ∈ N, then prove that f[f(x)] = x for all x.
Given, where a > 0 and n ∈ N.
We need to prove that f[f(x)] = x.
[∵ (am)n = amn]
⇒ f[f(x)] = x1
∴ f[f(x)] = x
Thus, f[f(x)] = x for all x.