# Trigo

**Geometry**Level pending

\[\begin{cases} \tan^{-1}(A)+\tan^{-1}(B)=\tan^{-1}(C) \\ A+B=C \\ A>1, B>1\end{cases}\]

If \(A\in Q\), \(\space\) \(C\in Z\), then \(B\in?\)

**Clarification:**

\(I\) denotes irrational number,

\(N\) denotes natural number,

\(Q\) denotes rational number,

\(Z\) denotes an integer.