Let $f: R \rightarrow R$ be a function defined $f(x) = \frac{x}{(1 + x^4)^{1/4}}$ and $g(x) = f(f(f(f(x))))$, then $18\int_0^{\sqrt{2\sqrt{5}}} x^2 g(x)\, dx$ (1) 33 (2) 36 (3) 42 (4) 39
Let $f: R \rightarrow R$ be a function defined $f(x) = \frac{x}{(1 + x^4)^{1/4}}$ and $g(x) = f(f(f(f(x))))$, then $18\int_0^{\sqrt{2\sqrt{5}}} x^2 g(x)\, dx$\\
(1) 33\\
(2) 36\\
(3) 42\\
(4) 39