f(x)
=x^2. sin(1/x) ; x≠0
=0 ; x=0
lim(x->0) f(x)
=lim(x->0) x^2. sin(1/x)
=0
=f(0)
x=0, f(x)连续
----------
f'(0)
=lim(h->0) [f(h) -f(0) ]/h
=lim(h->0) (h^2. sin(1/h)) /h
=lim(h->0) h. sin(1/h)
=0
=> f'(0) 存在
内容全部来源于网络收集，如有侵权，请联系网站删除：QQ：24596024