using a audio mixer with a mac book air

Im having trouble recording into the mac book air.

under sound in system preferences there is no option to change the input or output to anything other then internal built in. Even when using an rca adapter its not being read.

Does mac book air just not have an output function? can i not use a macbook air to record audio?

The output of the air is the built in speakers and Yes, it has an omnidirectional michrophone. From the tech specs on apple I dont see external jacks that will allow any devices other than USB.

If you want to, you could buy a USB microphone to record.

Can you tell us a bit more about what kinds of recordings you will be doing and what gear (mics, etc) you already have? That will give us more information to make recommendations.

Of course

Im using a Yamaha aw16g recording studio to record drums using a condensor mic (perception 420 xlr to xlr) and a dynamic mic (shure 57 xlr to 1/4 line in). then im trying to use a rca 3.5mm male to female adapter connected to a rca to 1/4 line input cable, from mac air to yamaha aw16g studio acting as a mixer. i was kind of hoping the rca adapter would allow the head phone jack of the mac to act as a input/output and give me the option to record in/out to the yamaha.

am i wrong? does the mac air only allow for a usb connection?

It seems it does.
The setup of what you would like to do isn't supported with a MBA. Plugging the cable that you have above will not transfer data, the headphone is another output jack and speakers, headphones etc. will only work.

Did you soundboard come with a CD? It may be a driver for the mixer, in that case a usb port may be on your mixer for that reason.

USB inputs are required.
Try these:
Amazon.com: Afunta(tm) 7.1 Channel USB External Sound Card Audio Mic Adapter USB Bus-powered Mode Highly Flexible Audio Interface Plug in and Play Kit Compatible with All Major Operating System Withou Driver for Windows 98se/me/2000/xp/2003/vista/win

Amazon.com: Griffin Technology 7725-IUAI iMic USB Audio Interface: Electronics
(I've had the iMic for several years - but I guess the newer cheaper ones will work, too.)