The number of solutions of \( \tan^{-1}4x + \tan^{-1}6x = \frac{\pi}{6} \), where \( -\frac{1}{2\sqrt{6}} < x < \frac{1}{2\sqrt{6}} \), is equal to:
\( 2 \)
\( 3 \)
\( 0 \)
\( 1 \)