Settings>General>Site address not working

Hi

I have a new installation of WP 3.5.1 in the folder https://www.mydomain.com/wp, and that is the address that is in the Site Address setting, but https://www.mydomain.com is not redirecting to the [wp] folder.

I believe I can manually fix this in .htaccess, but I’ve forgotten what I’m looking for… can someone please jog my memory? Or if I’m on the wrong track, point me in the right direction?

TIA
Cate