# Triple integral

1. May 7, 2009

### kieranl

1. The problem statement, all variables and given/known data
Sketch the solid E bounded by the cylinder x = y^2 and the planes z = 3 and x + z = 1, and write down its analytic expression. Then, use a triple integral to find the volume of E.

3. The attempt at a solution
Was wondering if someone could have a go at drawing this sketch? In mine, I thought i did it right but cant seem to obtain an enclosed surface. If x+z=1 was rather x-z=1 i would be able to but cant so far???

2. May 7, 2009

### HallsofIvy

The plane x+ z= 1 crosses the plane z= 3 when x+ 3= 1 or the line x= -2, z= 3, y= t. It crosses the cylinder $x= y^2$ in the line $x= t^2$, $y= t$, $z= 1- x= 1- t^2$.

I wonder if you weren't confusing $x= y^2$ with the $y= x^3$.

3. May 7, 2009

### Pinu7

I don't think you NEED to graph this.

y=(plus/minus) sqrt(x)

If that helps.

The range is x>0, so sqrt(x) is real.

If x>0, which is on top, z=3 or z=1-x?

EDIt: Is there an upper bound on x?

4. May 7, 2009

### kieranl

wat i have done is drawn the cylinder x = y^2 in the x-y plane and extended it along the z plane. Then i drew the z=3 plane and then drew a line z=1-x and it extended it along the y plane. But this does not end up enclosing a solid

5. May 7, 2009

### Pinu7

You are right, I think. There must be an upper x-limit for this to be a solid. Maybe, you have accidentally skipped some information.