lim(X趋向于0)(X平方/1-XtanX/1)

问题描述:

lim(X趋向于0)(X平方/1-XtanX/1)
写错了,是lim(X趋向于0)(1/x^2-1/XtanX)

lim(X趋向于0)(X平方/1-XtanX/1) =lim(X趋向于0)(tanx-x)/(x^2tanx) 由无穷小量代换 =lim(X趋向于0)(tanx-x)/(x^3) 上下求导 =lim(X趋向于0)(1/(cosx^2)-1)/(3x^2) 再求导 =lim(X趋向于0)[-2/(cosx)^3]*si...