# Cylindrical cordinace?

1. Oct 26, 2009

### fball558

cylindrical cordinace??

1. The problem statement, all variables and given/known data

this is a two part question and is multiple choice

part 1
Determine the type of the solid described by the given inequalities.
0 ≤ r ≤ 4, - pi≤ θ ≤ pi, -sqrt(16 − r^2) ≤ z ≤ sprt(16 − r^2)
a half-cylinder
a cylinder
a half-sphere
a sphere
a parallelepiped

part 2

Determine the type of the solid described by the given inequalities.
0<= theta <= pi/2 r <= z <= 5

a quarter of a cone
a half-cone
a quarter of a paraboloid
a half-paraboloid
a parallelepiped

graphing in cylindrical confuses me. any help on how to attach these would be great.
by looking at the second on i would assume it would be one the quarter somethings just because it is giong from 0 to pi/2 but dont know if that is right and if so how to tell the diff between cone or paraboloid??

2. Oct 27, 2009

### Staff: Mentor

Re: cylindrical cordinace??

Do you know how to graph polar coordinate in two dimensions? If you can graph a point with polar coordinates (r, $\theta$) in the plane, cylindrical coordinates in three dimensions aren't much more complicated. The third coordinate is a z coordinate.

Also, do you know the formulas for converting from Cartesian (or rectangular) coordinates to polar, and vice versa?