首页/题库/290℃/2024-05-07 02:20:20
⊿y=f﹙1+⊿x﹚-f﹙1﹚=1/﹙1+⊿x﹚-1=-⊿x/﹙1+⊿x﹚
⊿y/⊿x=-1/﹙1+⊿x﹚
∴f'﹙1﹚=lim﹙⊿y/⊿x﹚=-1