\[\boxed{\mathbf{1092}\mathbf{.}}\]
\[\sin\left( x - \frac{\pi}{2} \right) + 2\sin\frac{\pi}{2} -\]
\[- \sin\left( x + \frac{\pi}{2} \right) = - \cos x + 2 -\]
\[- \cos x = - 2\cos x + 2\]
\[- 2\cos x + 2 = 0\]
\[- 2\cos x = - 2\]
\[\cos x = 1.\]
\[Ответ:1.\]