Chapter 9: Vector Calculus
Section 9.4: Differential Identities
Example 9.4.1
If F=ux,y,z i+ux,y,z j+wx,y,z k, show that for sufficiently well-behaved u,v,w, the curl of F is solenoidal.
Solution
Mathematical Solution
Begin with ∇×F, the curl of F:
∇×F = wy−vzuz−wxvx−uy
Compute the divergence of the curl:
wy−vzx+uz−wxy+vx−uyz=wyx−vzx+uzy−wxy+vxz−uyz
The expression on the right vanishes because of the equality of the mixed partial derivatives, guaranteed, for example, by continuity of the second partial derivatives.
Maple Solution - Interactive
Initialize
Tools≻Load Package: Student Vector Calculus
Loading Student:-VectorCalculus
Tools≻Tasks≻Browse: Calculus - Vector≻ Vector Algebra and Settings≻ Display Format for Vectors
Press the Access Settings button and select "Display as Column Vector"
Display Format for Vectors
Define the Cartesian vector field F
Write the vector field as a free vector. Context Panel: Evaluate and Display Inline
Context Panel: Student Vector Calculus≻Conversions≻To Vector Field
Context Panel: Assign to a Name≻F
ux,y,z,vx,y,z,wx,y,z = →to Vector Field →assign to a nameF
Compute the divergence of the curl of F
Common Symbols palette: Del, dot product, and cross product operators
Context Panel: Evaluate and Display Inline
∇·∇×F = 0
Maple Solution - Coded
Load the Student VectorCalculus package and execute the BasisFormat command.
withStudent:-VectorCalculus:BasisFormatfalse:
Implement notational simplifications with the declare command in the PDEtools package
PDEtools:-declareux,y,z,vx,y,z,wx,y,z,quiet
Use the VectorField command in the Student VectorCalculus package to define F
F≔VectorFieldux,y,z,vx,y,z,wx,y,z =
Verify ∇·∇×F=0
Apply the Curl and Divergence commands from the Student VectorCalculus package.
DivergenceCurlF = 0
<< Chapter Overview Section 9.4 Next Example >>
© 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