(4)
lim (1-cos²x)/x²
x→0+
=lim sin²x/x²
x→0+
=lim (sinx/x)²
x→0+
=1²
=1
(5)
令4/x³=t，x→∞，则t→0
lim x³tan(4/x³)
x→∞
=lim 4tan(4/x³)/(4/x³)
x→∞
=lim 4tant/t
t→0
=lim 4(sint/cost)/t
t→0
=lim 4(sint/t)/cost
t→0
=4·1/cos0
=4/1
=4
内容全部来源于网络收集，如有侵权，请联系网站删除：QQ：24596024