已知lim(x→0) f(x)/(1-cosx) =2 求lim(x→0) [1+f(x)]^½

题目

已知lim(x→0) f(x)/(1-cosx) =2 求lim(x→0) [1+f(x)]^½

答案

lim(x→0)(1-cosx) f(x)/(1-cosx) =lim(x→0) f(x)=0
lim(x→0) [1+f(x)]^½=1