# Write inequalities to describe the region.

1. Sep 22, 2006

### steelphantom

I'm having some trouble figuring out the inequality that would satisfy this region:

The solid rectangular box in the first octant bounded by the planes x=1, y=2, and z=3.

Is it x >1, y >2 and z > 3? I can't think of anything else, really, and there's no answer in the back of the book since it's one of those darn even problems. Thanks!

2. Sep 22, 2006

### 0rthodontist

You want a box, not an infinite space. So the question implies that the box is also bounded by the same three planes that bound the first octant (what are those?)

3. Sep 22, 2006

### steelphantom

Ok, the planes that bound the first octant are x=0, y=0, and z=0.

The inequalities would then be 0<x<1, 0<y<2, and 0<z<3. Correct? Thanks for your help!

4. Sep 22, 2006

### 0rthodontist

Yeah, that's right.