Question 174
Is it true that for any nonzero integer numbers $a$ and $b$ the system of equations
$$
\begin{cases}
\tan(13x) \tan(ay) = 1, \\
\tan(21x) \tan(by) = 1
\end{cases}
$$
has at least one solution?
$$
\begin{cases}
\tan(13x) \tan(ay) = 1, \\
\tan(21x) \tan(by) = 1
\end{cases}
$$
has at least one solution?