lim(x趋向于0),tan6x / sin2x =
lim(x趋向于0),[(tan6x /6x)/ (sin2x/2x)]*(6/2)=
1×1×6/2=3
lim（x趋于1）(x^6-1)/ (x^10-1)=
lim（x趋于1）(x^6-1)’/ (x^10-1)’=
lim（x趋于1）6x^5/10x^9=
6/10
=3/5
lim(x趋向于0),tan6x / sin2x 等于多少呢
lim(x趋向于0),tan6x / sin2x =
lim(x趋向于0),[(tan6x /6x)/ (sin2x/2x)]*(6/2)=
1×1×6/2=3
lim（x趋于1）(x^6-1)/ (x^10-1)=
lim（x趋于1）(x^6-1)’/ (x^10-1)’=
lim（x趋于1）6x^5/10x^9=
6/10
=3/5