来源:学生作业帮 编辑:搜搜考试网作业帮 分类:数学作业 时间:2024/07/17 17:34:57
考研数学 导数定义问题~
![](http://img.wesiedu.com/upload/b/bd/bbd4a7b89a416223b1f37af016d11992.jpg)
A = lim[sin3x/x^3+f(x)/x^2] = lim[sin3x-xf(x)]/x^3 = 0 (0/0)
则 A = lim[3cos3x-f(x)-xf'(x)]/(3x^2) = 0,则 f(0)=3,(0/0)
A = lim[-9sin3x-2f'(x)-xf''(x)]/(6x) = 0,则 f'(0)=0,(0/0)
A = lim[-27cos3x-3f''(x)-xf'''(x)]/6 = 0,则 f''(0)=-9,