来自黄铁侠的问题
设f(x)具有连续的二阶可导,且f(0)二阶导=4,lim(x->0)f(x)/x=0,则lim(x->0)(1+f(x)/x)^1/x=?
设f(x)具有连续的二阶可导,且f(0)二阶导=4,lim(x->0)f(x)/x=0,则lim(x->0)(1+f(x)/x)^1/x=?
1回答
2020-12-23 17:42
设f(x)具有连续的二阶可导,且f(0)二阶导=4,lim(x->0)f(x)/x=0,则lim(x->0)(1+f(x)/x)^1/x=?
设f(x)具有连续的二阶可导,且f(0)二阶导=4,lim(x->0)f(x)/x=0,则lim(x->0)(1+f(x)/x)^1/x=?
lim(x->0)f(x)/x=0,所以f(x)=0lim(x->0)f(x)/x=lim(x->0)f'(x)=0,所以f'(x)=0设L=lim(x->0)(1+f(x)/x)^1/xln(L)=lim(x->0)ln(1+f(x)/x)/x=lim[x->0)(xf'(x)-f(x)]/[x^2+xf(x)]=lim(x->0)f''(x)/[2+f(x)/x+f'(x)]=...