I have just bought the spektrum dx3.0 and i am having trouble understanding some of the terminology. The following are the ones i don't understand:

1) Panic braking

2) Panic steering

3) What is exponential?

There are other things i don't understand but this will do for starters. If no one is sure can you point me in the right direction. Thanks in advance.

Well, exponential (expo for short) is adjusted to tune the relationship between the throttle trigger posistion and the amount of power (or throw, if refering to servos that operate an engine) actually applied to the powerplant.
stock expo should be at 0%, also known as linear, meaning that when the trigger is pressed down half way, it will provide the car with half the availiable throttle.
Note: this adjustment can also be used for steering as well.

Any other adjustment besides linear turns this acceleration path into a progressive (or exponential) climb towards full throttle at a different rate compared to the relationship of the trigger posistion.

Simply put, negetive expo will give more low end control feel, yet it will have full throttle similar to an off/on switch after a certain trigger posistion, and the exact oppisite for positive expo, Linear is the happy medium that most people should stay with.

I don't know wtf panic breaking or steering is used for, perhaps it just smooths out rough, jerking control when applied.

Hope this made sense/helps.

Thanks for that mate that made a lot more sense than the book did. As for the panic brakind and steering i think you hit the nail on the head. Thanks for that.

Panic steering is intended for oval racing where you normally may not need much steering throw, you turn it down to make the steering less sensitive at speed. But if you or one of your buddies decides to have a brain glitch and you end up sideways, the idea is that you hit the panic button and you have full steering to get yourself straightened out.

Panic braking I believe is just the maximum brake setting. The brakes you get if you panic and just push it all the way, instead of the normal different levels for different corners and such. Which ideally would prevent the need for panic steering.....

Cheers