I have these 3 equations. I tried to use wolfram alpha to graph in 3d, but did't succeed.
1) $x^2 + 2y^2 - 6x + 4y + 7 = 0$
2) $z^2 - 4z - 6x = 2$
3) $z = -y + 2$
I think that:
1) is a cylinder
2) is a cylinder
3) is just a sheet/plane
How close am I?
EDIT:
I also have: $x^2 + y^2 - 2x - 6y + 6z = 0$
I put the equation in the form $(x-1)^2 + (y-3)^2 + 6z = -10$... and I think this is also a cylinder... ?