____
lim |6-x - 2
x->2----------
___
|3-x - 1
希望大家看得懂..分子:根号下(6-x) - 2
分母:根号下(3-x) - 1
求极限..
...........____
lim........|6-x - 2 (根号内只有6-x)
x->2.......-------- (此为分数线)
...........___
..........|3-x - 1 (根号内只有3-x)
L'hospital .