control arms / sway bar

took car for brake inspection because of squeaking. mechanic says one control arm is broken, other is in bad shape. he says it is not safe to drive, will cause accident. is this true? what do the control arms do? if u change them do u need to change sway links at same time? please help!?!

If a control arm is "broken", you probably would not be able to drive the car at all. I would tow the car to another garage and get a second opinion, cuz something doesn't sound right.
In short....the control arm holds the tire/rim to the car, and it is a vital part of your suspension, so yes....the car is a danger to drive. Do not drive it until you get another opinion or get it repaired.
As far as the sway bar links/bushings, replace them if they are broken / missing / severely worn out. You can drive safely without the sway bar connected, but your steering/handling will be somewhat less responsive with a little more body roll.