question_answer

\[{{\tan }^{-1}}2x+{{\tan }^{-1}}3x=\frac{\pi }{{}},\] then x=

A)  \[-1\]                           

B)  \[\frac{1}{6}\]

C)  \[-1,\frac{1}{6}\]                      

D)  All of these

E)  None of these