tan3x 例7求lm 0 x→0sin5x 0 解lim tan 3x tan 3x 5x 3x =lim x-0 sin 5x x-0 3x sin 5x 5x 33 l×1 55 例8求lm 1-cosx 0 x→>0 2 0 2sin sIn 解原式=lm-2=m(2 x→0 2x-0x 2 2 Economic-mathematics 16-11 Wednesday, February 24, 2021Economic-mathematics 16 - 11 Wednesday, February 24, 2021 例8 . 1 cos lim 2 0 x x x − → 求 解 2 2 0 2 2sin lim x x x→ 原式 = 2 0 ) 2 2 sin lim( 2 1 x x x→ = . 2 1 1 2 1 2 =  = 例7 解 x x x sin5 tan3 lim →0 求 x x x x x x x x x x 5 3 sin5 5 3 tan3 lim sin5 tan3 lim 0 0 =   → → . 5 3 5 3 = 11 = “ ” 0 0 “ ” 0 0