College Algebra problems..

Hey, I have some question on college algebra

1. Is the line y=|x| symetric about the line y=x

2. How do you prove points A(-1,2) B(3,-2) C(-6,-3) are vertices of a right triangle?

3. given f(x)= 2x if 0<x<1, 1-x if 1=<x<2 , 0 if 1=<x=<3: find the domain,f(1), f(2), f(3), and f(0.1).

4. object thrown moves at a height in meters per second is represented With h(t)=20t-4.9t^2: find the height in x seconds, if time increases by 2 how migher is the object, how high does it move per second, if time increased by h how much higher is it?