I understand how to work with basic limits, and those ones under square roots, & how to implement that sinx/x=1 identity (& cos, tan).

But now, I'm coming across some really confusing stuff & my teacher simply is incapable of expressing these in intelligible terms.

here are some examples:

I'm not asking for answers to all of these. But can some one point me to some videos/material that can teach me how to solve & understand these particular types of limits? I have no idea where to begin!

Perhaps a sample calculation for just the first one too.

Thanks