f(x) = 4x
g(x) =
[tex] \sqrt{x^{2} \: - \: 1 } [/tex]
h(x) =
[tex] \sqrt{16x \: - \: 1} [/tex]
We want to check if h(x) = g(f(x))
So g(f(x)) =
[tex] \sqrt{(4x) {}^{2} - \: 1} [/tex]
Simplified;
g(f(x)) =
[tex] \sqrt{16x {}^{2} \: - \: 1 } [/tex]
But h(x) =
[tex] \sqrt{16x \: - \: 1} [/tex]
Hence g(f(x)) is not equal to h(x)
