如圖所示

熱心網友

注意:當x=0 的時候 f(x)=0 (1)再根據求導公式求f'(0)實際上是讓你求x趨向于0時f(x)/x的極限這類問題都這么解的。只要 滿足上面的條件(1)求f'(0)都是類似的解法

熱心網友

應用導數定義,有:f'(0)=Lim{x→0}[f(x)-f(0)]/[x-0],而f(0)=0,從而,f‘(0)=lim{x→0}[(x-1)(x-2)...(x-99)]=-99!

熱心網友

強 就一個字

熱心網友

強!

熱心網友

f'(0)=Lim{x→0}[f(x)-f(0)]/[x]=Lim{x→0}[(x-1)(x-2)(x-3)......(x-99)]==[(-1)(-2)(-3)......(-99)]=-99!

熱心網友

厲害

熱心網友

f(x)=x(x-1)(x-2)(x-3)......(x-99)f'(x)=x'[(x-1)(x-2)(x-3)......(x-99)]+x[(x-1)(x-2)(x-3)......(x-99)]'=f(x)/x+x{(x-1)'[(x-2)(x-3)......(x-99)]+(x-1)[(x-2)(x-3)......(x-99)]'}=f(x)/x+f(x)/(x-1)+x(x-1){(x-2)'[(x-3)......(x-99)]+(x-2)[(x-3)......(x-99)]'}=.......=f(x)/x+f(x)/(x-1)+f(x)/(x-1)+......+f(x)/(x-99)∴f'(0)=(x-1)(x-2)(x-3)......(x-99)=-99!