y=arctanx,则x=tany
arctanx′=1／tany′
tany′=(siny/cosy)′=cosycosy-siny(-siny)/cos²y=1/cos²y
则arctanx′=cos²y=cos²y/sin²y+cos²y=1/1+tan²y=1/1+x²
故最终答案是1/1+x²
希望能帮到你 y=arctanx,则x=tany
arctanx′=1／tany′
tany′=(siny/cosy)′=cosycosy-siny(-siny)/cos²y=1/cos²y
则arctanx′=cos²y=cos²y/sin²y+cos²y=1/1+tan²y=1/1+x²
故最终答案是1/1+x²
希望能帮到你