Suppose $f(x) = \frac{(2^x + 2^{-x})\tan x\sqrt{\tan^{-1}(x^2 - x + 1)}}{(7x^2 + 3x + 1)^3}$. Then the value of $f'(0)$ is equal to:
\( 0 \)
\( \sqrt{\pi} \)
\( \pi \)
\( \dfrac{\pi}{2} \)