MHB 15.4.20 volumn via triple integrals

Click For Summary
The discussion focuses on calculating the volume of a region in the first octant bounded by the coordinate planes and the surface defined by the equation z=4-x^2-y. The constraints for the triple integral are established as 0 ≤ z ≤ 4-x^2-y, 0 ≤ y ≤ 4-x^2, and 0 ≤ x ≤ z. The volume is computed using the triple integral V = ∫∫∫ dz dy dx, with specific limits for each variable. Participants are encouraged to explore the integral in different orders, specifically dydzdx and dydxdz. The conversation emphasizes verifying the correctness of the approach taken in the calculations.
karush
Gold Member
MHB
Messages
3,240
Reaction score
5
$\textsf{The region in the first octant bounded by the coordinate planes and the surface }$
View attachment 8112
$$z=4-x^2-y$$
$\textit{From the given equation we get}$
\begin{align*}\displaystyle
&0 \le z \le 4-x^2-y\\
&0 \le y \le 4-x^2\\
&0 \le x \le z
\end{align*}
$\textit{Thus the triple Integral results:}$
\begin{align*}\displaystyle
V&=\iiint\limits_{E} \, dzdyd
\quad =\int_{0}^{2}
\int_{0}^{4-x^2}
\int_{0}^{4-x^2-y}
\, dzdydx
\end{align*}
So just seeing if this is going the right direction
$\tiny{15.4.20}$
 
Last edited:
Physics news on Phys.org
karush said:
$\textsf{The region in the first octant bounded by the coordinate planes and the surface }$

$$z=4-x^2-y$$
$\textit{From the given equation we get}$
\begin{align*}\displaystyle
&0 \le z \le 4-x^2-y\\
&0 \le y \le 4-x^2\\
&0 \le x \le z
\end{align*}
$\textit{Thus the triple Integral results:}$
\begin{align*}\displaystyle
V&=\iiint\limits_{E} \, dzdyd
\quad =\int_{0}^{2}
\int_{0}^{4-x^2}
\int_{0}^{4-x^2-y}
\, dzdydx
\end{align*}
So just seeing if this is going the right direction
$\tiny{15.4.20}$

It's a good thing you didn't need that equation on the upper left.

Okay, now do it all over dydzdx and dydxdz.
 
Thread 'Problem with calculating projections of curl using rotation of contour'
Hello! I tried to calculate projections of curl using rotation of coordinate system but I encountered with following problem. Given: ##rot_xA=\frac{\partial A_z}{\partial y}-\frac{\partial A_y}{\partial z}=0## ##rot_yA=\frac{\partial A_x}{\partial z}-\frac{\partial A_z}{\partial x}=1## ##rot_zA=\frac{\partial A_y}{\partial x}-\frac{\partial A_x}{\partial y}=0## I rotated ##yz##-plane of this coordinate system by an angle ##45## degrees about ##x##-axis and used rotation matrix to...

Similar threads

  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
Replies
6
Views
2K
Replies
7
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
4
Views
2K