\[1)\ y = 2^{5x - 1}\]
\[y(x) = y(x + T)\]
\[2^{5x - 1} = 2^{5(x + T) - 1}\]
\[5x - 1 = 5(x + T) - 1\]
\[5x = 5(x + T)\]
\[x = x + T\]
\[T = 0.\]
\[Ответ:\ \ нет.\]
\[2)\ y = 2^{\sqrt{\cos^{2}x - 1}}\]
\[y(x) = y(x + T)\]
\[2^{\sqrt{\cos^{2}x - 1}} = 2^{\sqrt{\cos^{2}(x + T) - 1}}\]
\[\sqrt{\cos^{2}x - 1} = \sqrt{\cos^{2}(x + T) - 1}\]
\[\cos^{2}x - 1 = \cos^{2}(x + T) - 1\]
\[\cos^{2}x = \cos^{2}(x + T)\]
\[\frac{1 + \cos{2x}}{2} = \frac{1 + \cos{2(x + T)}}{2}\]
\[1 + \cos{2x} = 1 + \cos(2x + 2T)\]
\[\cos{2x} = \cos(2x + 2T)\]
\[2T = 2\pi\]
\[T = \pi.\]
\[Ответ:\ \ да.\]