Triple Integral: Having trouble finding my y bounds

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
3 replies · 7K views
Saladsamurai
Messages
3,009
Reaction score
7

Homework Statement



[tex]I=\int\int\int_E x^2e^ydV[/tex] where E is bounded by the parabolic cylinder

z=1-y^2 and the planes z=0 x=1 and x=-1

I know that the graph is a parabola that opens downwards and that has symmetry wrt the x-axis. It also stretches along the x-axis toward + and - infinity.

Can I get a hint here? :)
 
on Phys.org
It's pretty close to being trivial. The parabola z= 1- y2 has z= 0 at y= -1 and y= 1 so projecting down on to xy=plane, we get the square -1< x< 1, -1< y< 1. The z- integral is taken from 0 to 1- y2, the y integral from -1 to 1, and the x integral from -1 to 1.
 
Avodyne said:
Did you mean
[tex]I=\int\int\int_E x^2e^y\,dV[/tex] ?

I don't see any difference. So yes. :smile: