Blackboard Problem 1, ECE 333 Communication Systems

A superheterodyne radar is tuned to 2.8 GHz (1e9 Hz), and employs a local oscillator at 2.86 GHz.
  1. What is the intermediate frequency?
  2. What is the image frequency?
  3. What is the smallest intermediate frequency that you can use and prevent image frequency problems in the 2.8-3.0 GHz band?