Chapter 6: Applications of Double Integration
Section 6.2: Volume
Example 6.2.10
Find the volume that is enclosed by the surfaces z1=7−x2−y2 and z2=2 x+4 y−6 and that lies inside the right cylinder whose footprint in the plane z=0 is bounded by the curves y=x, y=2−x2, and x=0.
Solution
Mathematical Solution
Figure 6.2.10(a) shows the cross section of the right cylinder defining the region R over which the integration is to take place. Figure 6.2.10(b) shows the actual volume that is to be computed.
Figure 6.2.10(a) Cross section defining R
Figure 6.2.10(b) Requisite volume
The double integral ∫∫Rz1−z2 dA is most easily iterated in the order dy dx, resulting in
∫01∫x2−x213−x2−y2−2 x−4 y dy dx = 782105
Maple Solution - Interactive
Initialize
Tools≻Load Package: Student Multivariate Calculus
Loading Student:-MultivariateCalculus
Control-drag the equations zk=…, k=1,2.
Context Panel: Assign Name
z1=7−x2−y2→assign
z2=2 x+4 y−6→assign
Access the MultiInt command via the Context Panel
Write z1−z2 as the integrand. Context Panel: Evaluate and Display Inline
Context Panel: Student Multivariate Calculus≻Integrate≻Iterated Fill in both panes (see Figures 5.3.(1, 2)) and select "integral" for the Output
Context Panel: Evaluate Integral
z1−z2 = −x2−y2−2⁢x−4⁢y+13→MultiInt∫01∫x−x2+2−x2−y2−2⁢x−4⁢y+13ⅆyⅆx=782105
An alternate approach is to employ the task template in Table 6.2.10(a).
Tools≻Tasks≻Browse:
Calculus - Vector≻Integration≻Multiple Integration≻2-D≻Over a General 2-D Region
Integrate fx,y over a General Region
fx,y=
∫x=ax=b∫y=uxy=vxf ⅆy ⅆx
vx=
b=
ux=
a=
dy dx
Table 6.2.10(a) Solution by task template
A solution from first principles is given in Table 6.2.10(b).
Write an appropriate iterated integral and evaluate
Calculus palette: Iterated double-integral template
Context Panel: Evaluate and Display Inline
∫01∫x2−x2z1−z2 ⅆy ⅆx = 782105
Table 6.2.10(b) Solution from first principles
Maple Solution - Coded
Install the Student MultivariateCalculus package.
withStudent:-MultivariateCalculus:
Define the bounding surfaces z1 and z2.
z1≔7−x2−y2:z2≔2 x+4 y−6:
Top-level, using the Int and int commands
Intz1−z2,y=x..2−x2,x=0..1=intz1−z2,y=x..2−x2,x=0..1
∫01∫x−x2+2−x2−y2−2⁢x−4⁢y+13ⅆyⅆx=782105
Use the MultiInt command from the Student MultivariateCalculus package
MultiIntz1−z2,y=x..2−x2,x=0..1 = 782105
MultiIntz1−z2,y=x..2−x2,x=0..1,output=integral
∫01∫x−x2+2−x2−y2−2⁢x−4⁢y+13ⅆyⅆx
Use the MultiInt command with a pre-defined domain option
MultiIntz1−z2,x,y=Region0..1,x..2−x2 = 782105
MultiIntz1−z2,x,y=Region0..1,x..2−x2,output=integral
<< Previous Example Section 6.2 Next Section >>
© Maplesoft, a division of Waterloo Maple Inc., 2024. All rights reserved. This product is protected by copyright and distributed under licenses restricting its use, copying, distribution, and decompilation.
For more information on Maplesoft products and services, visit www.maplesoft.com
Download Help Document