Finding Solutions and Graphing F(X)

Greetings,

Hello again. I've got a few more questions this week. I've got another worksheet of problems and I need to graph them, however with these types of problems I'm not really sure how to convert the answers into something I can graph. I'm also not too sure about the f(x) thing, which I'm not entirely positive how to solve.

All of the problems below I need to graph...

1. $\displaystyle f(x) = x^2-6x+4$

I'm not entirely sure of myself on the f(x) concept. I'm probably wrong, but it seems like my instructor said that f(x) can be replaced with 0, but I'm probably wrong or maybe I just got part of what he was saying.

2. $\displaystyle g(x)=x^2+3x-10$

Is g(x) is the same as f(x), just using a different letter, or is it a different problem entirely?

3. $\displaystyle g(x)=-(x+2)^2$

If I understand it correctly, I'd just multiply everything in the parenthesis by -1 (-x, -2) and than have another set of the same numbers and multiple them together, correct? So (-x-2)(-x-2)... And than somehow formulate something to graph once I finish with the answer?

So, anyway, those are the ones I'm struggling with. Any help or advice would be much appreciated.

Thank you!