I bought a emax c2822 1200kv motor.... In this motor All three wires are black there us no sign of RAD.. BLACK OR YELLOW.   How I connect with esc ..how to know the positive or negative. .
thanks

A 3 phase Brushless motor like the one you have got does not comes with any positive or negative terminals.
Just connect the 3 wires from the motor to the 3 wires from the ESC.

If you find the motor to be rotating in the direction opposite to as intended then just switch any 2 wires out of the 3 and the motor direction will get reversed.

The motor is beeping continously. ..After I switch on tx then it works fine.... is this safe

Yep, those beeps are fine. It indicates that the Rx is not getting any signal from the Tx.

You need to calibrate throttle each time. Here's how to do it:
1. Switch on the Tx
2. Raise throttle stick to 100%
3. Connect LiPo to the ESC. You will hear some music followed by some beeps (usually 2-3 beeps)
4. Reduce throttle to 0% at once after hearing the beeps.
5. You will hear confirmatory beep(s) and/or music after that (varies from ESC to ESC)

That's it. You have just taught your ESC what sick position is 100% throttle and what is 0%.
Now the motor will rotate accordingly when you move the throttle stick.

Raise the throttle and the motor will now rotate.

Thanks a lot. ... It helps me