HDMI and AV cable both in PS3 at same time??

I have a sdtv in my room where my PS3 is, but recently ran a 35ft long HDMI cable from my PS3 to the HDTV in my living room.

I can only use the HDTV when my parents aren't watching it, so most of the time I have to play on the sdtv.

So rather than unplugging and replugging in the cables whenever i switch which tv im using, Can I just leave both the HDMI cable and the AV cable plugged into the PS3 and just switch the display settings when i want to use the HDTV??

Thanks in advance for the help

There's a very simple way to solve this mystery...

Plug in both cables and turn on both televisions. Then see if both are working. It's certainly not going to hurt your PS3, if that's what you're getting at. However, running the signal through 35 ft. of HDMI isn't a real great idea. You want to use the shortest cable possible. Also, your wireless controller is not going to be as responsive at a distance of 35 ft., especially if you're beaming the signal through a wall.