lim (sin (x/3))/x as x->0

题目

lim (sin (x/3))/x as x->0
答案是1/3

答案

lim (sin (x/3))/x (x趋于0）=lim1/3 (sin (x/3))/(x/3)=1/3lim (sin (x/3))/(x/3)=1/3
因为lim (sin (x/3))/(x/3)=1的