Limits more confusion

[Loki123]

So this is wrong. I am supposed to do first rationalization, but why? Why doesn't this work?

 

[Loki123]

So this is wrong. I am supposed to do first rationalization, but why? Why doesn't this work?
View attachment 30654

I used l'hopital rule btw

 

[Steven G]

Your limit must be in a particular form to use l'hopital's rule. What form was your limit in that you thought you could use l'hopital's rule?

 

[Loki123]

Your limit must be in a particular form to use l'hopital's rule. What form was your limit in that you thought you could use l'hopital's rule?

Well i read i can use it for infinity - infinity and this is - infinity+ infinity so i said why not

 

[Loki123]

Well i read i can use it for infinity - infinity and this is - infinity+ infinity so i said why not

Nevermind,
It can only be used for 0/0 and +or-infinity/+/-infinity, right?