I'm really struggling with these trig limits. I have three of them that I can't get straight, which I'll post separately. Sorry in advance for dropping all of these. I've stared at them endlessly, and don't know what else to do. Here's the first one:

I want to say that

, but I know this isn't correct. The answer to this is

, but I have no idea how to get there. We haven't covered L'Hospitals rule yet, so somehow I think that I have to get this down to

, but I just can't figure it out.

Can somebody please help?

Thanks.