The number of solutions of the equation \( \sin^{-1}\left[ x^{2}+\dfrac{1}{3}\right]+\cos^{-1}\left[ x^{2}-\dfrac{2}{3}\right]=x^{2} \), for \( x\in[-1,1] \) and \( [ x ] \) denotes the greatest integer less than or equal to \( x \), is:
\( 2 \)
\( 0 \)
Infinite
\( 4 \)