Functions + Piecewise

Help me please. Find the domain for the first two. Then find the domain range and the f(x) of the piecewise function.

http://img195.imageshack.us/img195/7416/math1111.jpg

1. Hint: Everything under the square root must be .

2. Hint: You can't have a zero denominator.

3. Your domain and range are right, assuming that the endpoints are not holes (I can't really see when the pic is so small).

You should be able to find the equations of the four lines which make the function.

thanks. here's what I did to the f(x)
http://img33.imageshack.us/img33/1879/math11111.jpg

Prove it said four lines.

You need linear formulas for , , , and . You are missing the middle two. What is the equation of the line through (0, 0) and (1, 2)? what is the equation of the line through (1,2) and (2, 1)?