Hi chukie! First, let me make your notation easier to read:
For the others:
1. When taking a limit, we only care about what happens to a function as it approaches a certain value, not what happens at that value. So, the limit of as will be the same as the limit of the first "piece."
2. For a function to be continuous at a point , three things must be true:
You should know the first 2 by answering the other two parts of this problem. So, take the limit of as . Then, if the value of this limit is , then is continuous at , and it will be discontinuous otherwise.
You should be able to find which value for makes the function continuous.