If the co-efficient of \( x^{9} \) in \( \left(\alpha x^{3}+\dfrac{1}{\beta x}\right)^{11} \) and the co-efficient of \( x^{-9} \) in \( \left(\alpha x-\dfrac{1}{\beta x^{3}}\right)^{11} \) are equal, then \( (\alpha\beta)^{2} \) is equal to __________.
