arccot-1,

platypus total testis suspensions were hybridised with a cot-1
arctanx的导数-arctanx的导数,arctanx,导数
(arctanx)'=1/(1 x²) (arccotx)'=-1/(1 x²)
反正切函数 y=arccotx 的图像符合上述要求 
已知arctan1 arctan2 arctanx=π,则x的值为( )