\[1)\ y = \sin\left( \cos x \right)\]
\[y(x + T) = y(x);\]
\[\sin\left( \cos(x + T) \right) = \sin\left( \cos x \right)\]
\[\cos(x + T) = \cos x\]
\[T = 2\pi.\]
\[Ответ:\ \ 2\pi.\]
\[2)\ y = \cos\left( \sin x \right)\]
\[y(x + T) = y(x);\]
\[\cos\left( \sin(x + T) \right) = \cos\left( \sin x \right)\]
\[\sin(x + T) = \pm \sin x\]
\[T = 2\pi\]
\[T = \pi.\]
\[Ответ:\ \ \pi.\]