\[\boxed{\mathbf{26}\mathbf{.}}\]
\[\textbf{а)}\ \frac{1}{\sqrt{x - 2}} = (x - 2)^{\cos x}\]
\[x - 2 > 0\]
\[x > 2.\]
\[M = (2; + \infty).\]
\[(x - 2)^{- \frac{1}{2}} = (x - 2)^{\cos x}\]
\[\textbf{б)}\ \left( x^{2} + 2 \right)^{\sin x} = \left( x^{2} + 2 \right)^{\cos x}\]
\[x \in R.\]
\[\textbf{в)}\ x^{\log_{\sqrt{x}}{2x}} = 4\]
\[x \in (0;1) \cup (1; + \infty).\]
\[2x = \pm 2\]
\[x = \pm 1.\]
\[Ответ:нет\ корней.\]
\[\textbf{г)}\ x^{2 - lg^{2}x - \lg x^{3}} - \frac{1}{x} = 0\]
\[x \in (0; + \infty).\]