西安毛子科技大学极限存在准则，两个重要极限XIDIAN UNIVERSITY例4 求 lim(sin↓+cos-)*YO解:原式=lim[(sin+cos) =lim(1+sin)1 Sin2. Sin3x22x=lim(1+sin =x>80x2sin=.xlim -2x2x->00lim sin=2xer-ox=e=e极限存在准则，两个重要极限 例4 求 解:原式 = 2 1 1 2 lim[(sin cos ) ] x x x x→ + 2 2 lim(1 sin ) x x x→ = + 1 2 sin 2 2 2 sin = lim(1+sin ) x x x x x   → 2 lim sin x 2 x x e →  = 2 sin lim x 2 x x e →  = = e