lim(x→0) tanx-sinx/x3方用洛

1个回答

lim(x→0) (tanx-sinx) / x³
= lim(x→0) tanx (1 - cosx) / x³ 先用等价无穷小代换 tanx x
= lim(x→0) (1 - cosx) / x²
= lim(x→0) sinx / (2x) 洛必达法则
= 1/2