Inverse Trigonometric Functions

If \(0 < x < {1 \over {\sqrt 2 }}\) and \({{{{\sin }^{ - 1}}x} \over \alpha } = {{{{\cos }^{ - 1}}x} \over \beta }\), then the value of \(\sin \left( {{{2\pi \alpha } \over {\alpha + \beta }}} \right)\) is :