I got a homework assignment to graph some nonlinear functions. I have no idea what they are, much less how to graph them. The problems are as follows:

1. $\displaystyle y = |x| - 2$

2. $\displaystyle y = -x$²$\displaystyle + 3$

3. $\displaystyle y = 2x$²$\displaystyle - 4$

4. $\displaystyle y = 2|x| + 3$

If somebody could help me with this, I'd be rather grateful.