1) I'm pretty sure you have that first one a little backwards. Perhaps x <= 2 or x >= 4?

2) It will help to separate the definition, so I'll use

f(x) = 3x-2

g(x) = x^2 + ax + b

We'll just use g(x) when we are around x = 3 and g(x) when one (1) or more away.

Your task is to create a continuous function. The only trick is matching up the endpoints, since (thankfully) they are the same).

f(2) = 4

f(4) = 10

We must make g(2) = 4 and g(4) = 10

That's all. Let's see what you get.